FAQ

Hydrovar

  1. When the pump doesn’t run for a long time can the Hydrovar protect against ceasing?
  2. What types of motors can be used with the Hydrovar unit?
  3. Where is the difference between a standard frequency converter and the Hydrovar unit?
  4. Is it necessary to maintain the Hydrovar in periods?
  5. Can the Hydrovar unit check any failures in the application?
  6. How is the scope of the Hydrovar and which applications are possible?
  7. Is it possible to use the Hydrovar for multipump systems?
  8. What is the difference between a variable frequency traditional and an Hydrovar?
  9. How much is the real energy saving of the Hydrovar and how long is the pay back period?
  10. How is the speed of the pumps split in a multipump system?

Pump

  1. What are the design criteria for Lowara pumps?
  2. What is a pump?
  3. What are the essential characteristics of a pump?
  4. What is the capacity (Q) of a pump?
  5. What is the total head (H) of a pump?
  6. How is measured the prevalence of a surface pump?
  7. How is measured the prevalence of a submersible pump?
  8. Dynamic head (Hd)
  9. What is volumic mass of a fluid (γ)?
  10. What is pressure?
  11. What is the effective power (Pu) for a pump?
  12. Is better to speak about pressure or total head for a pump?
  13. What is and how to calculate the efficiency of a pump (η)?
  14. What is required power (Pr) for a pump?
  15. What are the essential parts of a pump?
  16. What are the affinity laws?
  17. What are NPSH and suction power of a pump?
  18. Is the NPSH value related to the temperature of medium pumped?
  19. Is the NPSH value related to the elevation of application?
  20. What is and when pump work in cavitation condition?
  21. Can the Lowara pumps be used with liquids different from water?
  22. What are the selection criteria for a pump?
  23. What kind of pumps are produced and sold by Lowara?
  24. Why the+C62 pump cannot supply water?
  25. Why a pump cannot reach the required total head?
  26. Why a pump can leak through mechanical seal just from the first start-up?
  27. Why a pump can leak through mechanical seal after a long time of work?
  28. Why a pump can be noisy and vibrate?

Product Certification

  1. Lowara Products are certificated according to GOST rules?
  2. Are the reports test available for Lowara’s product?

Motor

  1. How to calculate the power (kW) absorbed by a motor?
  2. What are the limits to use the Lowara’s B62 motor?
  3. How is composed and what are the tension voltage of a supply electrical line?
  4. What are the design criteria for Lowara’s electrical motors?
  5. Can Lowara provide electrical motors in accordance with C7 UL-CSA standard?
  6. How are connected motor’s terminal box to the supply line?
  7. What is the direction of rotation for electrical motors?
  8. It is possible to reverse the rotation way on three phases motors?
  9. How must to be connected single phase motors on a three phase line?
  10. Are Lowara’s motor provided with earthing connection/ground and neutral wire connections?
  11. What are the supply voltage tolerances for Lowara’s motors?
  12. How the parameters of three phase motors change when there are voltage fluctuation at stable frequency?
  13. How torque value change on three phase motors if voltage and frequency vary?
  14. What are the selection criteria for an electrical motor?
  15. What are criteria to calculate the nominal apparent power (kVA) of an electrical motor?
  16. What are criteria to calculate nominal power (kW) of an electrical motor?
  17. What is the efficiency of the motor?
  18. In which condition we have the maximum value of efficiency and cos φ in an electrical motor?
  19. How to calculate the current drawn (A) by an electrical motor?
  20. What does “continuous service” means, in an eletrical motor?
  21. How to protect an electrical motor?
  22. Have the single phase Lowara motors an integrated protection?
  23. Why a motor overheat and must to be properly ventilated?
  24. What are the normal working conditions for an electrical motor?
  25. What is the maximum temperature value for Lowara’s motor casing?
  26. What is the maximum temperature admitted for Lowara’s motors?
  27. Is it possible to use a three phases motor as a single phase motor?
  28. What is the rpm of electrical motors?
  29. What is the sliding?
  30. What is the Service Factor (SF) of an eletrical motor?
  31. Can submersible motor run in horizontal position?
  32. Why an eletrical motor have an higher input current?
  33. Why a motor cannot start/run?
  34. What means finding two phases burned on a three-phase motor?
  35. What means finding three phases burned on a three phase motor?
  36. What does find an engine with starter winding burned means?
  37. What does find an engine running with winding burned means?

Conditions

  1. How you can choose/select a Lowara product?
  2. Where you can buy Lowara products?
  3. How is assured technical assistance to Lowara products?

Control Devices

  1. Why a pump controlled by GENYO device does not stop?
  2. Why a pump controlled by GENYO device does not start?

Other

  1. Is it possible to have the single-phase domo 7 doublebox with electrical panel, alarm and skid?
  2. Do you have pumps with grinders?
  3. If I increase the power of the motor, must I also increase the power of the inverter?
  4. Are pumps CEA SH SV suitable for liquid foodstuffs
  5. Do you manufacture pumps in Germany?
  6. Is it really necessary to fit a bleed valve for the boxes?
  7. Can your pumps mount Eff.1 motors
  8. When is it better to mount a Genyo rather than a pressure gauge and expansion tank
  9. Are your products certified to ATEX?
  10. What does total head mean?
  11. Are the unit manifolds available in stainless steel?
  12. Is it possible to have clean contacts on the control panel?
  13. The Hydrovar inverter is single-phase. Is the pump single-phase as well?
  14. How far away can I place the pressure transducer from the pump?
  15. How long does it take to receive spare parts or spare pumps and where do I get them from?
  16. Do I need an expansion tank when I mount the Hydrovar?
  17. How big must the tank for a draining system be?
  18. What cable must I use with the borehole pump?
  19. Which is better, a vortex or a single-channel pump?
  20. How many pumps can a Hydrovar control?
  21. What pump should I install for a family (1 bathroom, 1 kitchen, etc.)?
  22. Who is Lowara?
  23. Who is ITT?
  24. What does “R&CW” mean?
  25. Are Lowara pumps available in DIY stores?
  26. Where do I have to send pumps for service?
  27. Are your pumps acid-proofed?
  28. Are your pumps protected against dry running?
  29. Are your pumps maintenance-free?
  30. How can I get trained on Lowara products?
  31. What criteria must I use when choosing a pump for an application?
  32. What tools can I use to choose a Lowara product?
  33. Who is my local Lowara distributor?
  34. Do you have self-priming pumps?
  35. Are your pumps cheaper than those of your competitors?
  36. What does “EMEA” mean?
  37. How long is your warranty?

Hydrovar

1. When the pump doesn’t run for a long time can the Hydrovar protect against ceasing?
The Hydrovar starts an automatic test run of the pumps to avoid ceasing after a long period of no operation – the time interval is programmable.
2. What types of motors can be used with the Hydrovar unit?
Hydrovar units can be effectively mounted on all available standard three phase asynchronous motors for centrifugal pumps or fans.
3. Where is the difference between a standard frequency converter and the Hydrovar unit?
The Hydrovar hardware and software is especially developed for pumping applications and so the parameters you can program are optimal for this.
4. Is it necessary to maintain the Hydrovar in periods?
The Hydrovar control unit does not require special maintenance.
However, the cooling fan and the vents should be freed of dust occasionally.
5. Can the Hydrovar unit check any failures in the application?
Hydrovar have a built in delivery control protection logic. In case the pressure sensor finds that there was not enough pressure built up after a certain time of operation it switches off and tries again up to a max. of five times.
This avoids dry running of the pump and running out of the curve.
6. How is the scope of the Hydrovar and which applications are possible?
Besides the standard pressure or differential pressure control according to a constant set value, Hydrovar’s microprocessor is able to follow a defined curve (i.e. pipe- work characteristic) without additional devices or control units.
7. Is it possible to use the Hydrovar for multipump systems?
In multipump units each Hydrovar is able to communicate with up to seven more Hydrovar units following the actual demand of the system without additional control units.
8. What is the difference between a variable frequency traditional and an Hydrovar?
The Hydrovar hardware and software are specially developed for pumping and so the parameters are optimized for these applications.
9. How much is the real energy saving of the Hydrovar and how long is the pay back period?
Huge amounts of energy can be saved in the HVAC industry by using variable speed drives. A mere 20% drop in speed of centrifugal pumps can save as much as 50% in energy.
It is impossible to provide a fixed value because it depends on many parameters (type of pump, operation time, varying load conditions,…)
10. How is the speed of the pumps split in a multipump system?
In multipump systems you can take the MULTICONTROLLER Mode (one pump with max. speed and the following with the required speed or a special feature (SYNCHRON CONTROL) allows all operating pumps to run at the same speed – the total system demand is split up in equal portions to each operating pump.

Pump

11. What are the design criteria for Lowara pumps?
Lowara pumps are designed to move clear and clean water.
All our performance curves are plotted testing our pumps in clear clean water.
12. What is a pump?
A pump is a manufacturing machine that transforms the mechanical energy supplied by a motor into hydraulic energy by the impeller.
13. What are the essential characteristics of a pump?
The essential characteristics of a pump are:

  • Capacity (Q);
  • Total head (H);
  • Effective power (Pu).
14. What is the capacity (Q) of a pump?
The scope Q is the volume of moved liquid delivered by a pump in the time unit. And usually is measured in:

  • litres per second (l/s);
  • litres per minute (l/min);
  • cubic metres per hour (m³/h);
  • Imperial gallons per minute (Imp.gpm) or
  • US gallons per minute (US gpm).
    It reduces if the pump works in cavitation.
15. What is the total head (H) of a pump?
Known as well as head, difference in level, difference in height. It is define as the increase in energy that a pump can give to each kg of fluid that crosses through the impeller; it serves to bring the fluid at a certain level (upper than the starting’s level), or travel in a tube (or in the air) a certain distance. It is expressed in feet or meters (of water column).
16. How is measured the prevalence of a surface pump?
To determine the total head value of a surface pump it is necessary to measure, during normal working conditions, the head value at suction (with a vacuum/pressure gauge) and delivery (with a pressure gauge) ports taking the same reference level (datum plane). According to the installation system, on suction port the head value could be:

  1. negative (lower than gauge’s zero): the liquid level is lower than pump axis;
  2. positive (higher than gauge’s zero): the liquid level is higher than pump axis.

For application of type 1) pump’s total head is the sum of the read values, while for application of type 2) pump’s total head is the difference of the read values.
If pipes at suction and discharge sides have different diameters it is necessary to calculate and insert the dynamic head (see below) value.

17. How is measured the prevalence of a submersible pump?
To define the total head value of a submersible pump it is sufficient to read, during the normal working conditions, the head value on the pressure gauge added with the dynamic head value and with the difference between pressure gauge and water surface.
18. Dynamic head (Hd)
It is the part of total head related to fluid speed. Dynamic head Hd is given by the following formula:
Hd = v²/2g where:
V is the fluid’s speed on the measure inlet (in m/s);
g is the gravity acceleration (in m/s²).
If suction and deliver ports have different diameter the dynamic head is due to the difference between dynamic heads on suction side and on delivery side.
If suction and delivery ports have the same diameter there is not dynamic head.
19. What is volumic mass of a fluid (γ)?
It is the weight of a fluid for volume’s unit. It is expressed by kg/dm³ o kg/l (1l = 1dm³)
20. What is pressure?
Pressure is the application of force to a surface, and the concentration of that force in a given area.
In the hydraulic field pressure is related to specific weight of a liquid and it is measured in Pascal (1 Pa = 1N/1m²).
21. What is the effective power (Pu) for a pump?
It is the mechanical energy transferred by the pump’s impeller to the moved fluid as kinetic and potential energy.
It is measured in kW and it depends from 3 characteristics:

  • Capacity (Q);
  • Total head (H);
  • Volumic mass of fluid.

It is calculated by the following formula:
Pu = (Q*H*g)/(h*K) where:
Q is the capacity in m³/h;
H is total head in m;
g is specific mass of fluid in kg/m³;
h is hydraulic efficiency (for the pump only);
K is equal to 367 for Pu in kW.

22. Is better to speak about pressure or total head for a pump?
When discussing the performance of a pump is usual to adopt the term “pressure” meaning “total head”, but this is wrong; we have to use only term “total head”.
Pressure and total head are related by the following formula:
Pa = H [m] * y [kg/m³] * 0.102 [N/m²].
23. What is and how to calculate the efficiency of a pump (η)?
The efficiency of a pump is the value of ratio between effective and requested power (Pu and Pr).
η = Pu/Pr.
It is expressed in % to facilitate its comprehension and comparison.
24. What is required power (Pr) for a pump?
Required power is the power that a pump absorbs from a motor to give to the moved medium the effective power.
A part of the absorbed power is dissipate for friction when liquid moves through pipes, valves, filters and/or hydraulic parts of pump (impeller, diffuser (s)). They are not recoverable.
25. What are the essential parts of a pump?
In a pump the basic components are:

  • pump body: inside this part run the impeller;
  • impeller: part that supplies energy to the fluid;
  • shaft: machine member that transfers the rotatory motion to the impeller;
  • seal system: machine member that separates the hydraulic part (for surface pumps) or the motor (for submersible products) to the external ambient, to avoid that the fluid enter or exit, respectively.
26. What are the affinity laws?
The affinity laws express the mathematical relationship between several variables involved in pump performance.
They apply to all type of centrifugal and axial flow pumps running in laminar flow condition.

  1. when speed changes and impeller diameter remains the same:
    Q1/Q2 = N1/N2;
    H1/H2 = (N1/N2)2;
    P1/P2 = (N1/N2)3.
  2. when impeller diameter changes and speed remains the same:
    Q1/Q2 = D1/D2;
    H1/H2 = (D1/D2)2;
    P1/P2 = (D1/D2)3.
27. What are NPSH and suction power of a pump?
It is the acronym of Net Positive Section Head and it is the total suction head – in m – determined at the suction nozzle and correct to datum, less the vapour pressure of the liquid – always in m -. In other words it is an analysis of energy conditions of suction side of a pump to determine if the liquid will vaporize at the lowest pressure point in the pump. To ensure that a pump works correctly along the whole performances curve, it is necessary, for each point of the curve that:
NPSH available > NPSH requested.

28. Is the NPSH value related to the temperature of medium pumped?
Yes of course, because with temperature, changes also the vapour pressure of the liquid.
29. Is the NPSH value related to the elevation of application?
Yes, it is necessary to add to the NPSH value showed in our catalogue from 0 m for applications at sea level up to 3.3 m for applications at 3,000 m on the sea level.
30. What is and when pump work in cavitation condition?
Cavitation is a term used to describe the phenomenon that occurs in a pump when there is not sufficient NPSH available (NPSHa). The pressure of the liquid is reduced to a value equal to or below its steam pressure and small steam bubbles or pockets being to form. As these steam bubbles move along the impeller blades to higher pressure area, they rapidly collapse.
The collapse (or “implosion”) is so rapid that it may be heard as a rumbling noise; these working condition can cause serious damage to the impeller or to other hydraulic parts.
31. Can the Lowara pumps be used with liquids different from water?
Please, verify with our sales network technical feasibility to move different liquids than clear clean water verifying, on the basis of chemical characteristics of medium to move, the resistance to corrosion for components, rubber, seal parts and surfaces and, on the basis of the volumic mass or the specific weight, if it is necessary to increase of one or more sizes electrical motor.
32. What are the selection criteria for a pump?
A pump is chosen on the basis of application target, like (not exhaustive list):

  • medium to move and its chemical composition;
  • performances required (Q and H);
  • pipes (material and length);
  • curves and valves presence;
  • open or pressurized system.
33. What kind of pumps are produced and sold by Lowara?
Surface pumps
These are hydraulic machines suitable to work in a dry and covered surface. They must not be immersed into liquid to move.
This kind of product includes single or multi stage pumps for horizontal or vertical operation.

Circulator and in-line pumps
Very similar to the surface pumps, manufactured with suction and discharge mouths in-line, they are suitable to be installed and used in closed system (i.e. heating system).

Drainage pumps
These pumps are specific designed to move sewage or waste water also with suspensions or filaments.
They can be divided in different family according to:

  • kind and chemical composition of the liquid to move (clear drainage water, sewage water, waste water, industrial sludge);
  • the impeller design (single or multichannels, Vortex, Grinder).

These pumps, with particular devices, can be used as a surface pump.

Submersible pumps
These kind of pumps can run only if they are completely immerged into liquid to move, so they are used exclusively in deep well.

34. Why the+C62 pump cannot supply water?
Surface pumps
It is necessary to verify priming and running condition of the pump:

  • pump body and suction pipe have to be full of water;
  • level between liquid surface and pump axle have to be to 8 m;
  • pump rotation way;
  • suction valve perfectly closed (to assure that suction pipe and pump body remain full of water);
  • suction valve, suction and delivery pipes, pump’s impeller clean and not clogged;
  • valves on suction and delivery pipes correctly assembled and opened.

Submersible pumps
It is necessary to verify installation condition of the pump:

  • maximum immersion depth;
  • delivery pipe and pump’s impellers not clogged;
  • NRV correctly installed.
35. Why a pump cannot reach the required total head?
Check if the pump was correctly selected and dimensioned for the required use, then verify if:

  • Measuring instruments (flow meter, pressure gauge) are checked and reliable;
  • pump is moving water or a liquid having volumic mass and/or density like water;
  • pump is working inside the performance curve limits;
  • pump is not working in cavitation condition;
  • pump is correctly primed (or it does not lose priming);
  • moved liquid have not got air bubble inside.
36. Why a pump can leak through mechanical seal just from the first start-up?
Probably this failure is due to a random assembling error.
Please address to our Service Partner (see list on Lowara WEB site) to repair the product.
37. Why a pump can leak through mechanical seal after a long time of work?
The reasons of this particular kind of failure have to be searched in:

  • normal wear of mechanical seal faces’ materials;
  • mechanical seal faces’ material and chemical composition of moved liquid incompatibility;
  • presence of abrasive suspensions into moved liquid (excessive wear);
  • thermal shock due to presence of air inside liquid or for cavitation operating condition.
38. Why a pump can be noisy and vibrate?
It should be verify:

  • with some measure the noise level, before to claim a product as noisy;
  • application condition that have to be optimized to avoid a similar defect.

Pump noisy and vibrations could be due to:

  • cavitation working condition;
  • wired ball bearings;
  • rotating part that touches static part (i.e. impeller —> pump body).

Product Certification

39. Lowara Products are certificated according to GOST rules?
All our products can be supplied with a copy of GOST certificate which should be required under the order.
40. Are the reports test available for Lowara’s product?
There are many documents that must be obtained under order of the product. Please contact our sales network for all your needs.

Motor

41. How to calculate the power (kW) absorbed by a motor?
The power absorbed from a supply line is given:

  • for three phases motor: P1 = (1.73 * V * I * cosr)/1000 (kW);
  • for single phase motor: P1 = (V * I *cosr)/1000 (kW)
42. What are the limits to use the Lowara’s B62 motor?
  1. ALTITUDE (height above sea level)
    Usually a standard motor can be using without particulars limitations, until 1000 metres of height. Over 1000 metres the air density decrease, and with it decrease the air’s ability to cool the motor too.
    For higher altitudes, motor derating are required.
  2. AMBIENT TEMPERATURE
    The cooling medium is usually the air surrounding the motor; the ambient temperature have not to exceed 40° C.
    For higher temperature, motor derating is required;
  3. MAXIMUM NUMBER OF STARTS PER HOUR
    Define by motor’s Manufacturer on the basis of motor’s size.
    They are reported on our IOM (Instruction Operating Manual).
43. How is composed and what are the tension voltage of a supply electrical line?
The 3 phases electrical supply line at low tension are composed by three wires (conventionally marked with L1, L2, L3) with or without neutral wire.
Neutral wires are connected to the centre of star connection of the generator or of the voltage transformer (low tension side).
To have a single phase supply line it is possible to connect charges between two phases wires (for line without neutral wire) or between a phase and the neutral wires.
The voltage between two main wires (L1-L2 or L2-L3 or L1-L3) is the line voltage (or network voltage).
The voltage between a main wire and the neutral wire is named phase voltage.
44. What are the design criteria for Lowara’s electrical motors?
Surface electrical motors of Lowara are designed, manufactured and tested according to the criteria established by the International standard IEC 60034 series and labelled with European mark “CE”.
45. Can Lowara provide electrical motors in accordance with C7 UL-CSA standard?
Please, verify with our sales network technical feasibility.
Some products are already customized and we can supply them equipped with motors manufactured according to Northern American standard.
46. How are connected motor’s terminal box to the supply line?
Three phases motors have to be connected to the main wires.
The nominal voltage of the motor label have to be the same of the network voltage (rated voltage). Motor’s Terminal connections can be to Star (S) or Delta (D).
If for motors manufactured with squirrel-cage rotors a S-D start up is required, the terminal connection must be to Delta (D).
Motors with windings in 230/400V, when the insertion is direct to the supply line, can be used at 230V (D) or 400V (S) after checking of correct connection on terminal box.
47. What is the direction of rotation for electrical motors?
Single phase motors:
The direction of rotation is due to the internal connections of windings loops during the stator’s manufacturing.

Three phase motors:
Terminal connections on three phase motors are signed as U1, V1, W1 in order to guarantee the correct phases sequence to assure the motor’s clock rotation (seeing motor from cooling fun site).
This rules is valid for all our electrical motors, and do not depends from the motors’ voltage or size, also if those could be rotate on anticlockwise. A check of the correct sequence of phases is required by a Technician before to connect the motor to the electrical supply.

48. It is possible to reverse the rotation way on three phases motors?
To reverse the rotation way on a three phase motor you have to reverse two wires on terminal connections.
49. How must to be connected single phase motors on a three phase line?
Single phase motor are connected to two phases wires (for line without neutral wire) or between a phase and the neutral wires. If more single phase motors have to be connected, it is strongly recommended to distribute their connections on the main wires of the three phases.
50. Are Lowara’s motor provided with earthing connection/ground and neutral wire connections?
All our motors are equipped with a connection for the protection wire on the:

  • terminal box for surface motors;
  • motor casing for submersible pump motors;
  • lower support for well pump motors.
51. What are the supply voltage tolerances for Lowara’s motors?
1~ motors:
220-240V 50Hz: ± 6%;
230 V 50 Hz: ± 10%;
3~ motors:
220-240/380-415V 50 Hz: ± 6%;
230/400V 50Hz: ±10%
52. How the parameters of three phase motors change when there are voltage fluctuation at stable frequency?
In a three phase motor starting and maximum torque change – more or less – with the square of the voltage variation rapport while the input current change with the same rapport.
If the deviation of the supply voltage respect the nominal voltage value remain within the tolerances allowed, motor will continue to give the nominal power.
The overheating of the motor can be exceeded by 10°C.
If the frequency variation is inside the ± 5% of nominal frequency, motor continue to give the nominal power while speed change in the same rapport with the frequency variation.
53. How torque value change on three phase motors if voltage and frequency vary?
If voltage and frequency vary in proportion to the same effect (in + or -), within the tolerance limits, there are not modifications on the magnetic conditions and motor develops more or less the normal mechanical torque.
54. What are the selection criteria for an electrical motor?
To choose an electrical motor is necessary to consider:

  • work load (power required);
  • type of service;
  • # of starts per hour;
  • speed variations required;
  • electrical supply network condition;
  • cooling fluid temperature;
  • installation height.
55. What are criteria to calculate the nominal apparent power (kVA) of an electrical motor?
Nominal apparent power is done:

  • for three phases motor: P = (1.73 * V * I)/1000 (kVA);
  • for single phase motor: P = (V * I)/1000 (kVA)
56. What are criteria to calculate nominal power (kW) of an electrical motor?
The nominal power is the mechanical power available at the motor’s shaft and it is done:

  • for three phases motors:
    P2 = (1.73 * V * I * cosr * η)/1000 (kW)
  • for single phase motors:
    P2 = (V * I * cosr * η)/1000 (kW)

Motor nominal power have to be equal – or higher – than power requested from manufacturing machine.
A motor over sizing means:

  • higher starting current;
  • bigger electrical protection and supply wires dimensions;
  • more expensive service because power factor (cosr) and, in certain condition, the efficiency for partial load are worse than at full load.
57. What is the efficiency of the motor?
Efficiency is the value of the ratio between nominal power (P2) and power absorbed from the electrical supply line (P1).
η = P2/P1
It is expressed in % to simplify evaluation/comparison.
58. In which condition we have the maximum value of efficiency and cos φ in an electrical motor?
Electrical motors are designed by Manufacturers to reach the maximum efficiency value at 75% of nominal power, while the maximum value of cos φ is reached at full nominal power.
59. How to calculate the current drawn (A) by an electrical motor?
  • For three phases motors:
    I = 1000 * P1/(1.73 * V * cosρ) (A);
  • for single phase motors:
    I = 1000 * P1/(V * cosρ) (A)
60. What does “continuous service” means, in an eletrical motor?
All Lowara’s motors are manufactured for continuous service (S1). Continuous service means to work in constant condition for a time period sufficient to reach the thermal balance.
61. How to protect an electrical motor?
Fuses:
Fuses are not an electrical protection for the motor but only a protection against shorts circuit.

Overload cut-off (circuit switch or thermal relay):
The overheating motor for overloading or for the lack of a phase is avoided by using an overload cut-off.
On the data label you can find the value of the nominal current that have to be used to set overload cut-off devices.

62. Have the single phase Lowara motors an integrated protection?
Our standard 1~ motors are protected by an automatic reset overload protection up to 1.5 kW; this products have to be used under surveillance (or through an external additional safety devices like thermal switch).
As power beyond the 1.5 kW overload protection must be provided and installed by, for example, buying one of our electrical panel.
63. Why a motor overheat and must to be properly ventilated?
The motor life is related of its insulation windings, regardless of the length of bearings (wear motor member). Heating is a consequence of the energy losses due to the transformation inside motor from electrical energy to mechanical energy. Heating developed by the energy losses is accumulated inside motor and bring out through ventilation. The steady state is reached when the quantity of heating produced by motor is the same of the quantity of heating gets rid of; in continuous service condition this happens in 3÷5 hours.
64. What are the normal working conditions for an electrical motor?
The nominal power of a motor, indicated on data label is valid if the following conditions are respected:

  • type of service;
  • frequency of 50 or 60 Hz;
  • maximum ambient temperature: 40°C;
  • installation height lower than 1.000 meters on see level.

If working condition are out of the above mentioned limits it is necessary to reduce the load applied or to increase the motor’s size.

65. What is the maximum temperature value for Lowara’s motor casing?
The modern way to manufacture motors blocking the windings and the stator to the motor casing, in order to increase the heating transmission, gives the external temperature of the casing more or less equal to the windings temperature.
66. What is the maximum temperature admitted for Lowara’s motors?
The maximum temperature admitted in environments where our motors are installed is 40°C.
Higher temperature have influence on motor’s life so it is necessary to apply a lower load or increase the size.
During normal working condition of the motor it is necessary to have available fluid (air or liquid) to cooling motor.
67. Is it possible to use a three phases motor as a single phase motor?
To use a 3 phases motors connected as 1 phase condenser (1 phase) supply electrical line is possible but strongly not recommended because you’ll have to calculate and insert an adequate capacitor between two phases wirings and the nominal power of the 3 phases motor supplied as 1 phase motor decrease of about 20÷30% and the start torque is reduced of 25÷30% than nominal torque.
68. What is the rpm of electrical motors?
To calculate the synchronous speed of an AC motor we use the following formula:
(120 * frequency) / # of poles.
Frequency are measured in Hz, while the number of poles are a function of design.
For a 2 poles, 50 Hz motor the synchronous speed is: (120 * 50)/ 2 = 3000.
69. What is the sliding?
The above mentioned velocity in an AC motor is theoretical because the real speed is lower for slip that is the difference between the speed of the rotating magnetic field (which is always synchronous) and the rotor in a non- synchronous induction motor. It is expressed as a percentage of synchronous speed. Slip generally increases with an increasing torque. The full load speed of a motor is lower of 2÷7% (slip of 2÷7%) than no load speed.
70. What is the Service Factor (SF) of an eletrical motor?
To ensure the right rotation, cables connections are marked with a little label applied on each supply cable wire; if labels are lost, probably the supply cable are not correctly connected to the electrical line (R-U; S-V; T-W) so, the motor turn in the right way but the magnetic field inside stator has to be compensated by a higher current.
It is necessary to try to reverse motor cables connection on the terminal box up to find the right rotation way and the right input current.
71. Can submersible motor run in horizontal position?
Lowara submersible motors are specifically designed and manufactured to run in horizontal position. It is necessary to assure the right cooling of motor.
72. Why an eletrical motor have an higher input current?
The causes of an higher input current in an electrical motor could be:

  • motor with different nominal tension/frequency than the supply line;
  • a phase is lost (3~ motors);
  • winding interrupted;
  • winding to ground;
  • wrong electrical connections on the terminal box (or inside stator);
  • there was not exchange between Star/Delta connection;
  • tension outside of the tolerance limits (under or over voltage);
  • wrong size of motor in relation to the applied load;
  • pump is moving a fluid with specific weight or density > than water;
  • hydraulic or mechanical parts blocked;
  • wrong rotor.
73. Why a motor cannot start/run?
It is necessary to check that motor is correctly supplied (electrical connections into control box or to plug).

If all is ok, cut off the electrical supply and verify:

  • safety and control devices protections conditions (fuses, thermal relays, overload release, …);
  • capacitor condition (for 1~ motor);
  • winding’s insulation resistance (a lowest value is a clear sign that motor is seriously compromised);
  • motor and pump can rotate free (for surface products).
74. What means finding two phases burned on a three-phase motor?
Motor was connected to a single phase line (internal motor connections in Star) or motor was connected to a three phase line but a phase was not supplied.
75. What means finding three phases burned on a three phase motor?
Motor overloaded or not correctly cooled. Similar damages could be avoid using motor through adequate electro-mechanical protections.
76. What does find an engine with starter winding burned means?
Wrong capacitor (too high capacity).
77. What does find an engine running with winding burned means?
Motor did not start; verify electrical connections, capacitor condition and if hydraulic part are free to rotate.

Conditions

78. How you can choose/select a Lowara product?
On Lowara WEB site you can download all the data sheets and the selection program LOOP4U.

79. Where you can buy Lowara products?
Lowara products can be purchased at our Distributors or at our Service Point reported in our WEB site.

80. How is assured technical assistance to Lowara products?
By our European Branches or Distributors. A network of Service Centre/Service Partner have been created in each European country (the list is available on http://www.lowara.com/service/).

Control Devices

81. Why a pump controlled by GENYO device does not stop?
Please, check that:

  • the flow of water through GENYO is < 0.7 l/min;
  • the pressure of the pump is higher at least 0.5÷1 bar (depending to GENYO models) than start pressure.
82. Why a pump controlled by GENYO device does not start?
Please, check that:

  • Genyo’s electronic card is not damaged;
  • electrical connections are corrected in order to be sure that Genyo device and pump are correctly supplied;
  • pump body and suction pipe are full of water or dry run protection intervenes;
  • water column on Genyo’s delivery is < of 20 m, otherwise the pressure of water column on the flow valve does not allow to open it.

Other

83. Is it possible to have the single-phase domo 7 doublebox with electrical panel, alarm and skid?
On request, you can fit DOMO 7 SG pumps inside the DOUBLEBOX commanded by floats with control panel, but in the fixed connection version only
84. Do you have pumps with grinders?
Yes, the DLG models.
85. If I increase the power of the motor, must I also increase the power of the inverter?
You must select the size of converter that allows maximum absorption of the electric motor.
86. Are pumps CEA SH SV suitable for liquid foodstuffs
The AISI316 stainless steel version of these models with EPDM gaskets are suitable for drinking water and can be certified to WRAS.
87. Do you manufacture pumps in Germany?
As ITT Lowara, since the summer of 2007 we have 5 production facilities in Europe: two in Italy, one in Austria, one in Poland and one in the UK. We produce pumps, booster sets, control boxes and motors in Italy; pumps, booster sets and speed drive systems in Austria; efficiency class 1 motors in Poland, and pumps in the UK. In Germany, we offer our customers the products we have in stock. Mounting DIN/DVGW pressure boosters, modifying pumps according to customer requirements with special sliding ring gaskets are operations that we perform to the highest standards at our facilities.
88. Is it really necessary to fit a bleed valve for the boxes?
It is always best to have a bleed valve as the gas produced by the fermenting sewage is potentially hazardous.
89. Can your pumps mount Eff.1 motors
Currently, only on request though this will shortly be a Lowara standard.
90. When is it better to mount a Genyo rather than a pressure gauge and expansion tank
Definitely when there is not enough space to install and adequately service the sphere kit. Additionally, the GENYO is fitted with an electronic timer for preventing excessive hourly start-ups.
91. Are your products certified to ATEX?
For models with standardised motors, the entire product can be certified to ATEX.
92. What does total head mean?
Simply put, it is the sum of the pressure required to use the pump and the pressure drops in the system.
93. Are the unit manifolds available in stainless steel?
Yes, in both AISI304 and AISI316 on request
94. Is it possible to have clean contacts on the control panel?
These can be configured on request
95. The Hydrovar inverter is single-phase. Is the pump single-phase as well?
No, the pump must be three-phase 230 V
96. How far away can I place the pressure transducer from the pump?
Using a 2×0.75mm shielded cable, up to 100 m from the pump motor
97. How long does it take to receive spare parts or spare pumps and where do I get them from?
The normal delivery time for all Lowara standard products is 3 to 5 days. Spare parts or replacement pumps are available at Lowara Deutschland GmbH Großostheim, Lowara dealers and Lowara service contractors
98. Do I need an expansion tank when I mount the Hydrovar?
That depends on the application. It is generally sufficient to have an expansion tank with a capacity of approximately 10% of the maximum capacity of the pump expressed in L/m
99. How big must the tank for a draining system be?
The capacity of the tank is calculated according to the pumps installed and the number of hourly start-ups.
100. What cable must I use with the borehole pump?
For the exposed part us a shielded motor cable and earth the sheath-shield at both ends. The submerged part does not require shielding
101. Which is better, a vortex or a single-channel pump?
That depends on the sewage. Single-twin channel impellers are best for liquids containing elevated quantities of long and fibrous materials, such as sewage from pig farms, textile industries and unfiltered primary sludge. Retracted vortex impellers let more solids through but do not perform as well as channel pumps.
102. How many pumps can a Hydrovar control?
One Hydrovar controls one pump. It can control units of up to 4 pumps with a serial cascade connection
103. What pump should I install for a family (1 bathroom, 1 kitchen, etc.)?
A DOMO 7VX is generally sufficient.
104. Who is Lowara?
Lowara, established in 1968, is a European pump manufacturer. Its headquarters is located near Vicenza in Italy. Lowara produces high performance pumps in stainless steel and cast iron in various manufacturing facilities in Europe. Products range from water supply pumps to industrial pumps and construction service systems. With nine sales offices and highly qualified dealers all over Europe and in the Middle East, Lowara offers a comprehensive dealer network. A constantly high product quality is guaranteed by using the Six Sigma quality safety programme.
105. Who is ITT?
ITT is a steadily growing worldwide enterprise with a turnover of 7.81 billion USD (2006). The offer covers products for the aeronautics and aerospace sectors, the use of pumps in all sectors of industry and construction and electronic components for information technology and telecommunications.
106. What does “R&CW” mean?
R&CW is an abbreviation of Residential & Commercial Water
107. Are Lowara pumps available in DIY stores?
No, only from specialised distributors.
108. Where do I have to send pumps for service?
You must send them to the Lowara Service Point or, after contacting Customer Care, to the Lowara Service Centre at Großostheim.
109. Are your pumps acid-proofed?
To choose the right pumps for chemical applications, we do need further details on hydraulic operations as well as on the type , concentration and temperature of the liquid.
110. Are your pumps protected against dry running?
No, unprotected centrifugal pumps are not generally designed for dry running. It is important to give your dealer as much information as possible about the system in which the pump is used. Inlet pressure, the type of liquid to be pumped, together with relative density, viscosity and temperature, for example, are required in order to allow Lowara to recommend the right pump with the right gaskets for a long operating lifetime.
111. Are your pumps maintenance-free?
Yes.
112. How can I get trained on Lowara products?
Yes, we provide training courses in all areas (products, general and specific pump technology, hydraulics, and practical applications). Please consult your sales manager or get in touch with our Großostheim headquarters (Tel. 06026-943-0 lowarade.info@itt.com)
113. What criteria must I use when choosing a pump for an application?
You must choose the pump depending on the application. Please contact your local area sales manager or Lowara distributor.
114. What tools can I use to choose a Lowara product?
You may choose the right appropriate pump by consulting the data sheet and the pump selection programme – similar to LOOP4U – (both can be downloaded from our homepage).
115. Who is my local Lowara distributor?
You can get Lowara products from your local distributor and Services Points which are divided by sales areas/postcodes. Please see the corresponding page on our homepage.
116. Do you have self-priming pumps?
Yes, our product portfolio also includes two ranges of self-priming pumps: BG (self-priming electric pumps) and SP (self-priming side channel pumps).
117. Are your pumps cheaper than those of your competitors?
Lowara aims to give its customers the highest standards of quality and service and delivery times, all at a reasonable price.
118. What does “EMEA” mean?
EMEA is an abbreviation of Europe, Middle East and Africa.
119. How long is your warranty?
Unless otherwise expressly authorized in writing, by specifying a longer period or different conditions, R&CW states that, for a period of twelve (12) months from delivery date, all Products supplied are free from defects in materials and workmanship, and conform to the applicable specifications. Either the delivery documentation or the invoice must be provided to prove delivery date. In absence of such documents, the production date appearing on the product label may suffice.