Grundfos HS User manual

HS
Horizontal split case pump
GRUNDFOS INSTRUCTIONS
Installation and operating instructions

Declaration of Conformity
1: HS pump complete with motor and base frame:
We Grundfos declare under our sole responsibility that the products HS, to
which this declaration relates, are in conformity with the Council Directives
on the approximation of the laws of the EC Member States relating to
— Machinery (98/37/EC).
Standard used: EN ISO 12100.
— Electromagnetic compatibility (89/336/EEC).
Standards used: EN 61000-6-2, EN 61000-6-4, EN55011 Gr. 1 Class A
and EN61000-4 chapter 2, 3 & 8.
— Electrical equipment designed for use within certain voltage limits
(73/23/EEC).
Standard used: EN 60204-1.
2: HS bare shaft pump:
We Grundfos declare under our sole responsibility that the products HS, to
which this declaration relates, are in conformity with the Council Directive
on the approximation of the laws of the EC Member States relating to
— Machinery (98/37/EC) and fulfils Annex II B.
Standard used: EN ISO 12100.
An HS bare shaft pump must not be put into service until the machinery
into which it is incorporated has been declared in conformity with the
Directive.
Bjerringbro, 1 July 2006
Svend Aage Kaae
Technical Director
2

3
CONTENTS
Page
1. General description 3
2. Delivery and handling 3
2.1 Delivery 3
2.2 Handling 3
2.3 Temporary storage 4
3. Applications 4
3.1 Pumped liquids 4
4. Identification 4
4.1 Type key 5
5. Operating conditions 5
5.1 Ambient temperature 5
5.2 Liquid temperature 5
5.3 Maximum pressure 5
5.4 Minimum inlet pressure 5
5.5 Maximum inlet pressure 5
5.6 Minimum flow rate 5
5.7 Maximum flow rate 5
6. Mechanical installation 5
6.1 Location 5
6.2 Foundation 5
6.3 Vibration dampers 5
6.4 Expansion joints 6
6.5 Foundation and alignment procedure 6
7. Piping 8
7.1 System types 8
7.2 General information 8
7.3 Suction piping 9
7.4 Valves in suction piping 10
7.5 Discharge piping 10
8. Electrical connection 10
8.1 Frequency converter operation 10
9. Start-up 11
9.1 Pre-start checks 11
9.2 Starting 11
9.3 Operating checks 11
9.4 Operating at reduced flow and/or head 11
9.5 Frequency of starts and stops 12
10. Maintenance 12
10.1 General information 12
10.2 Frequency of inspections 12
10.3 Lubrication 12
11. Frost protection 13
12. Service 13
13. Fault finding 14
14. Disposal 16
1. General description
Grundfos type HS horizontal split case pumps are supplied
either
as complete pump with motor, base frame, approved coupling
guard and CE mark
or
as bare shaft pump without CE-mark.
These instructions apply to both types.
The HS pump can be driven by an electric motor or other type of
driver. In the following we assume that the pump is driven by an
electric motor.
2. Delivery and handling
2.1 Delivery
The pump is delivered from factory in a crate or wooden box
specially designed for transport by fork-lift truck or a similar
vehicle.
Upon receipt, check the pump visually to determine whether any
damage has happened during transport or handling. Check
especially for
1. broken or cracked equipment, including base frame, motor or
pump feet and flanges
2. broken motor fan cover, bent eye bolts or damaged terminal
box
3. missing parts.
Parts or accessories are sometimes wrapped individually or
fastened to the equipment.
If any damage or losses have occurred, promptly notify Grundfos’
representative and the carrier’s agent.
2.2 Handling
Fig. 1 How to lift and handle HS pumps.
Note: Use shackles at all four corners.
Fig. 2 How to lift and handle HS bare shaft pumps.
Prior to installation, read these installation and
operating instructions. Installation and operation
must comply with local regulations and accepted
codes of good practice.
TM03 2692 4805TM03 4290 1906
When unloading the pump, lift equally at four or more
points on the base frame. Do not lift by the motor or
pump. Do not lift by the flanges or by the eyebolts on
the motor.

4
2.3 Temporary storage
If the pump is not to be installed and operated soon after arrival,
store it in a clean, dry place with slow, moderate changes in
ambient temperature. Protect the pump from moisture, dust, dirt
and foreign bodies. Prior to and during storage we recommend
these precautions:
1. Ensure that the bearings are filled with the recommended
grease to prevent moisture from entering around the shaft,
see 10.3 Lubrication.
2. Ensure that suction and discharge ports of the pump and all
other openings are covered with cardboard, wood or masking
tape to prevent foreign objects from entering the pump.
3. Cover the unit with a tarpaulin or other suitable covering if it is
to be stored where there is no protective covering.
4. Rotate the shaft 2 turns every 2 weeks to prevent corrosion of
the bearing surfaces and the stuffing box/shaft seal faces due
to moisture.
3. Applications
Grundfos HS horizontal split case pumps are typically used for
• circulation in heating, ventilating, air-conditioning and cooling
systems
• liquid transfer and pressure boosting in various industrial
systems
• liquid transfer in irrigation systems.
3.1 Pumped liquids
Thin, clean and non-aggressive liquids, not containing solid
particles or fibres. Do not pump liquids that will attack the pump
materials chemically.
When pumping liquids with a density and/or viscosity higher than
that of water, use motors with correspondingly higher outputs.
The stuffing box packing rings/mechanical shaft seal O-rings
chosen must be suitable for the liquid to be pumped.
Special stuffing box packing rings/shaft seal O-rings may be
required if the pump is used for pumping treated water
• at temperatures above 80°C (176°F)
• containing additives to prevent system corrosion, calcareous
deposits, etc. (this may be the case in heating and ventilating
systems).
When pumping water mixed with glycol, it may be necessary to
use another shaft seal. For further information, please contact
Grundfos.
4. Identification
The type designation and rating information of Grundfos
horizontal split case pumps are stated on the nameplate, see
fig. 3. The type designation includes serial number, model
number, size and type.
Permanent records for this pump are kept under its year-week
code and serial number (pos. 5 and 6) and this number must
therefore be stated in all correspondence and spare parts orders.
Fig. 3 Nameplate CE-marked HS pump
Fig. 4 Nameplate HS bare shaft pump without CE-mark
TM03 2104 3705TM03 4291 1906
Pos. Description
1 Type designation
2 Model
3 Product number
4 Place of production
5 Production year and week
6 Serial number
7 Maximum pressure and temperature
8 Rated flow rate
9 Head at rated flow rate
10 Speed
11 Country of production
HS 80-65-240 / 220 1/1 F A BBQV 1
A 96XXXXXX P2 01 27 0001
180 57 2900
16/80
MADE IN SINGAPORE
123456
1
0
8
9
11
7
HS 80-65-240 / 220 1/1 F A BBQV 1
A 96XXXXXX P2 01 27 0001
180 57 2900
16/80
MADE IN SINGAPORE
123456
10
8
9
11
7

5
4.1 Type key
The type key is an explanation of the product type designation,
see fig. 3, pos. 1.
5. Operating conditions
5.1 Ambient temperature
Maximum +40°C.
5.2 Liquid temperature
The maximum liquid temperature marked on the pump nameplate
depends on the mechanical shaft seal used.
Max. temperature for NBR: +80°C
Max. temperature for Viton: +90°C.
5.3 Maximum pressure
The maximum pressure is stated on the nameplate, see fig. 3.
5.4 Minimum inlet pressure
The minimum inlet pressure must correspond to the NPSH curve
for the pump + a safety margin of minimum 0.5 metres head.
NPSH appears from the data booklet and WebCAPS.
5.5 Maximum inlet pressure
Inlet pressure + pressure when the pump is running against
closed valve must never be higher than the maximum pressure
stated on the nameplate.
5.6 Minimum flow rate
A minimum flow rate equal to 30% of the flow rate at maximum
efficiency is needed at all times. Flow rate and head at maximum
efficiency are stated on the nameplate.
5.7 Maximum flow rate
The maximum flow rate must not exceed 120% of the value
stated on the nameplate. If the maximum flow rate is exceeded,
cavitation and overload may occur.
6. Mechanical installation
6.1 Location
Install the pump as close as possible to the supply of pumped
liquid, with the shortest and most direct suction pipe practical.
Install the pump with sufficient accessibility for inspection and
maintenance. Allow ample space and headroom for the use of an
overhead crane or hoist sufficiently strong to lift the unit.
Make sure there is a suitable electricity supply available for the
motor.
6.2 Foundation
We recommend that you install the pump on a concrete
foundation which is heavy enough to provide permanent and rigid
support for the entire pump. The foundation must be capable of
absorbing any vibration, normal strain or shock. As a rule of
thumb, the weight of the concrete foundation should be 1.5 times
the weight of the pump or unit. For further information on the
building of the foundation, see section 6.5 Foundation and
alignment procedure.
Fig. 5 HS pump with base frame mounted on a concrete
foundation (B) with expansion joints (A) and vibration
dampers (C)
6.3 Vibration dampers
To prevent vibrations from being transmitted to the building or the
pipework, we recommend you to isolate the pump foundation
from buildings by means of vibration dampers. In order to select
the right vibration damper, you need this information:
• Forces transferred through the damper.
• Motor speed. In the case of speed control, this must also be
taken into account.
• Desired dampening in % (recommended value: 70%).
The selection of vibration damper differs from installation to
installation. In certain cases a wrong damper may increase the
vibration level. Vibration dampers should therefore be sized by
the supplier of the vibration dampers.
HS 85 x65 x240 /220 1/1 F A BBQV 1
Type range
Nominal diameter
of suction port
Nominal diameter
of discharge port
Nominal impeller diameter
Actual impeller diameter
Pump version:
1 = Standard
2 = Extended
3 = Two-stage, through-bore
4 = Two-stage, non-through-bore
/1 = With standard coupling
/2 = With spacer coupling
/3 = Bare shaft pump
Code for pipework connection:
F = DIN flange
G = ANSI flange
Code for materials (pump housing and impeller):
A = Cast iron pump housing with cast iron
impeller
B = Cast iron pump housing with bronze impeller
E = Spheroidal graphite iron (GGG40) pump
housing with bronze impeller
S = Cast iron pump housing with stainless steel
impeller
N = Stainless steel pump housing with stainless
steel impeller
Z = All bronze
Code for shaft seal or stuffing box
Directon of rotation:
1 = Clockwise
2 = Counter-clockwise
TM03 2500 4405

6
6.4 Expansion joints
Expansion joints provide these advantages:
• Absorption of thermal expansion and contraction of pipework
caused by variations in liquid temperature.
• Reduction of mechanical influences in connection with
pressure surges in the pipework.
• Isolation of structure-borne noise in the pipework (only rubber
bellows expansion joints).
Note: Do not fit expansion joints to make up for inaccuracies in
the pipework, e.g. centre displacement or misalignment of
flanges.
The expansion joints should be fitted at a minimum distance of
1-1.5 flange diameters away from the pump, both on the suction
and the discharge sides. This prevents turbulence in the joints,
thus ensuring optimum suction conditions and minimum pressure
drop on the discharge side.
At high water velocities (> 2.4 m/s), we recommend you to fit
larger expansion joints matching the pipework.
6.5 Foundation and alignment procedure
The foundation and alignment procedure has five steps:
1. Pouring of foundation
2. Shimming of base frame
3. Preliminary alignment
4. Grouting
5. Final alignment
6.5.1 Pouring of foundation
We recommend the following procedure to ensure a good
foundation.
1. Pour the foundation without interruptions to within 15 - 30 mm
of the final level. Use compactors to ensure that the concrete
is evenly distributed. The top surface should be well scored
and grooved before the concrete sets. This provides a bonding
surface for the grout.
2. Embed foundation bolts in the concrete as shown in fig. 6.
Allow enough bolt length to reach through grout, shims, lower
base frame, nuts and washers.
Fig. 6 Typical foundation bolt design
Let the foundation cure for several days before the base frame is
shimmed and grouted
6.5.2 Shimming of base frame
Fig. 7 Shimming of base frame and levelling of pump
1. Lift/jack up the base frame to the final level, 15 - 30 mm above
the concrete foundation, and support the base frame by
means of blocks and shims both at the foundation bolts and
midway between bolts, see fig. 7.
2. Level the base frame by adding or removing shims under the
base frame, see fig. 7.
3. Tighten the foundation bolt nuts against the base frame. Make
sure the piping can be aligned to the pump flanges without
putting strain on pipes or flanges.
6.5.3 Preliminary alignment
The pump and motor are correctly aligned on the base frame from
the factory. Some deformation of the base frame may occur
during transport and it is therefore essential to check alignment at
the installation site prior to final grouting.
A flexible coupling will only compensate for minor misalignments
and should not be used to compensate for excessive
misalignment of the pump and motor shafts. Inaccurate alignment
results in vibration and excessive wear on the bearings, shaft or
wear rings.
Carry out alignment of motor and pump by placing shims of
different thickness under motor and pump, respectively. If
possible, replace several thin shims with one thick shim.
The preliminary alignment procedure has three steps:
1. Checking coupling clearance
2. Checking parallel alignment
3. Checking angular alignment.
1. Checking coupling clearance
Check that the gap between the coupling halves is equal to the
values in the table and that the keyways are 180° displaced.
If the pump is installed on a foundation with vibration
dampers, fit expansion joints on both sides of the
pump. The pump must have these flexible
connections both at the discharge side and the
suction side to allow the pump to move up and down.
TM03 0190 4504
5-10 mm
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Bolt length
above base
frame
Thickness of
base frame
15 to 30 mm
allowance for
grout
Base frame
Top of foundation
left rough
Pipe sleeve
Lug
Washer
TM03 2804 4805
Before starting work on the pump, make sure that the
electricity supply has been switched off and that it
cannot be accidentally switched on.
For a coupling
with an outside
diameter of ø [mm]...
the coupling clearance
[mm] must be:
Nominal Tolerance
ø90 to ø180 3 0/–1
ø200 to ø315 4 0/–1
ø355 to ø630 5 0/–1

7
2. Checking parallel alignment
Place a straight edge across both coupling rims at the top, the
bottom and both sides, see fig. 8. After each adjustment, recheck
all features of alignment. Parallel alignment is correct when the
measurements show that all points of the coupling faces are
within ±0.2 mm of each other.
Fig. 8 Checking parallel alignment
3. Checking angular alignment
Insert a pair of inside calipers or a taper gauge at four points at
90° intervals around the coupling, see fig. 9. Angular alignment is
correct when the measurements show that all points of the
coupling faces are within ±0.2 mm of each other.
Fig. 9 Checking angular alignment
Recheck coupling clearance and tighten the set screws on the
couplings
6.5.4 Grouting
Grouting compensates for uneven foundation, distributes weight
of unit and prevents shifting. Use an approved, non-shrinking
grout and proceed as follows:
1. Build a strong formwork around the foundation to contain the
grout.
2. Soak top of concrete foundation thoroughly, then remove
surface water.
3. Fill the formwork with grout up to a thickness of 15 - 30 mm.
Allow grout to dry thoroughly before attaching piping to pump
(24 hours is sufficient time with approved grouting procedure).
4. When the grout has thoroughly hardened, check the
foundation bolt nuts and tighten if necessary.
5. Approximately two weeks after the grout has been poured, or
when the grout has thoroughly dried, apply an oil base paint to
the exposed edges of the grout to prevent air and moisture
from getting in contact with the grout.
Fig. 10 Sectional view of foundation with foundation bolt,
grouting and base frame
6.5.5 Final alignment
Make final alignment after the base frame has been properly
fastened and the grout has dried thoroughly according to
instructions.
Proceed like this:
1. Check direction of rotation, see 9.1.5 Direction of rotation.
2. Let the pump run until it has reached its operating temperature
under normal operating conditions (approx. 1 hour).
3. Check alignment on the coupling by means of a dial gauges,
see below.
Checking coupling alignment by means of dial gauges
Start the procedure by removing coupling pins and checking that
the motor shaft and pump shaft can turn freely.
Fig. 11 Dial gauge arrangements;
the end view of the coupling is seen from the motor
The coupling alignment procedure has four steps:
1. Parallel alignment - vertically
2. Parallel alignment - horizontally
3. Angular alignment- horizontally
4. Angular alignment - vertically.
1. Parallel alignment - vertically
1. Mount dial gauge (2) in position 0° (12 o’clock), see fig. 11.
2. Make index lines on the two coupling halves, see fig. 11.
3. Set the dial gauge pointer to zero, turn motor and pump shaft
simultaneously until dial gauge is in position 180° (6 o’clock)
and check that the index lines are still in line.
4. Read dial gauge (2). If dial gauge shows a deflection
exceeding ±0.2 mm, add or remove shims under the motor
until the reading of the dial gauge is within the allowable
tolerance of ±0.2 mm.
TM03 0209 4504TM03 0213 4504TM03 2946 4905
5-10 mm
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Base frame
Grout
Levelling wedges
or shims
Top of foundation
(rough)
15 to 30 mm
grout
Formwork
Make final alignment by shimming the motor only.
TM03 0210 4504TM03 2939 4905
0°
90°
180°
270°
Dial gauge (2) for
parallel alignment
Index
line
Dial gauge (1) for
angular alignment

8
2. Parallel alignment - horizontally
1. Turn motor and pump shaft 90°.
2. Set the dial gauge pointer to zero, turn motor and pump shaft
180° and check that the index lines are still in line.
3. Read dial gauge. If dial gauge shows a deflection exceeding
±0.2 mm, move the motor sideways until the reading of the
dial gauge is within the allowable tolerance of ±0.2 mm.
4. Remove dial gauge (2).
3. Angular alignment - horizontally
1. Mount dial gauge (1) in position 90° (3 o’clock), see fig. 11.
2. Make index lines on the two coupling halves, see fig. 11.
3. Set the dial gauge pointer to zero, turn motor and pump shaft
simultaneously until dial gauge is in position 270° (9 o’clock)
and check that the index lines are still in line.
4. Read dial gauge (1). If the dial gauge shows a deflection
exceeding ±0.2 mm, move the motor sideways until the
deflection is halved.
5. Set the dial gauge pointer to zero, turn motor and pump shaft
simultaneously until dial gauge is in position 90° (3 o’clock)
and read dial gauge (1) again.
6. Now the reading should be within the allowable tolerance of
±0.2 mm. If not - repeat the procedure.
4. Angular alignment - vertically
1. Turn motor and pump shaft until dial gauge (1) in position 0°
(12 o’clock).
2. Set the dial gauge pointer to zero, turn motor and pump shaft
simultaneously until dial gauge is in position 180° (6 o’clock)
and check that the index lines are still in line.
3. Read dial gauge (1). If dial gauge shows a deflection
exceeding ±0.2 mm, add or remove shims under the motor
until the deflection is halved.
4. Set the dial gauge pointer to zero, turn motor and pump shaft
until dial gauge is in position 0° (12 o’clock) and read dial
gauge (1) again.
5. Now the reading should be within the allowable tolerance of
±0.2 mm. If not - repeat the procedure.
6. Remove dial gauge (1).
Note: Coupling tolerances may differ from coupling make to
coupling make. For the standard mounted pin and bush coupling
the allowable tolerance is ±0.2 mm. For other coupling types,
please see the coupling data supplied with the pump.
Finish the alignment procedure by refitting and tightening the
coupling pins.
7. Piping
7.1 System types
The Grundfos HS horizontal split case pumps can be installed in
two types of system:
1. Closed systems or open systems where the liquid level is
above the pump inlet, meaning that a certain suction head will
be available.
2. Open systems where the liquid level is below the pump inlet,
meaning that the pump will be operating with a suction lift.
7.2 General information
When installing the piping, observe these precautions:
• Always run the piping to the pump.
• Do not move pump to the piping. This could make final
alignment impossible.
• Make sure that both suction and discharge piping are
independently supported near the pump so that no strain is
transmitted to the pump when the flange bolts are tightened.
Use pipe hangers or other supports with necessary spacing to
provide support.
• When expansion joints are used in the piping system, fit the
joints at a minimum distance of 1-1.5 flange diameters away
from the pump, both on the suction and the discharge sides.
This prevents turbulence in the joints, thus ensuring optimum
suction conditions and minimum pressure drop on the
discharge side.
• Install piping as straight as possible and avoid unnecessary
bends. Where necessary, use 45° or long sweep 90° fittings to
reduce friction loss, see fig. 19.
• Make sure that all piping joints are tight.
• Where flanged joints are used, ensure that inside diameters
match properly.
• Remove burrs and sharp edges when making up joints.
• Make sure that the piping does not cause stress or strain in
the pump.
• Provide for expansion of pipe material when hot liquids are to
be pumped.
TM03 2941 4905TM03 2942 4905TM03 2940 4905
Do not operate unit without ensuring that all guards
are in place.

9
7.3 Suction piping
The following procedure applies to
• closed systems and open systems where the liquid level is
above the pump inlet
• open systems where the liquid level is below the pump inlet.
Many NPSH (Net Positive Suction Head) problems can be
avoided if the suction piping is properly installed.
• Ensure that pressure losses are minimized and sufficient liquid
will flow into the pump.
• Make the suction piping is as short in length and as direct as
possible, and never smaller in diameter than the pump suction
port.
• Avoid air pockets or turbulence in the suction pipe, see fig. 12.
Fig. 12 NOT recommended suction pipe installations
• Install the suction pipe sloping upwards towards the suction
port. Any high point in the pipe will be filled with air and thus
prevent proper operation of the pump. When reducing the
piping to the suction port diameter, use an eccentric reducer
with the eccentric side down to avoid air pockets, see fig. 13.
Fig. 13 Upward sloping suction pipe
• Never use a straight, concentric reducer in a horizontal suction
pipe, as it tends to cause the formation of air pockets at the
top of the reducer and the pipe, see fig. 14.
Fig. 14 A concentric reducer will cause an air pocket to be
formed at the top of the reducer.
• Make sure that the liquid flow is evenly distributed to both
sides of the double suction impellers.
There is always an uneven, turbulent flow through an elbow.
So if an elbow is installed in the suction pipe near the pump in
a position other than vertical, more liquid will enter one side of
the impeller than the other, see fig. 15. This will result in
heavy, unbalanced thrust loads overheating the bearings,
causing rapid wear and reducing the hydraulic performance.
Fig. 15 Unbalanced loading of a double suction impeller due
to uneven flow through an elbow close to the pump.
Fig. 16 NOT recommended suction pipe installation
The problems of uneven suction flow to the pump may be solved
in two different ways:
• Install a length of straight pipe of at least 10 times the
diameter of the suction pipe, see fig. 17.
Fig. 17 Recommended suction pipe installation with a length
of straight pipe
• or install a suction diffuser direct on the suction port of the
pump, see fig. 18.
Fig. 18 Pump installation with suction diffuser (1)
The sizing and installation of the suction piping is
extremely important.
TM03 2518 4505TM03 2541 4505TM03 2519 4505TM03 2540 4505
Air pocket
Turbulent flow
Air pocket
TM03 0212 4504TM03 2542 4505TM03 2539 4505TM03 2590 1109
Water pressure increases here
causing a greater flow to one side
of the impeller than to the other
Uneven flow
DN
10 x DN
1

10
Generally recommended suction pipe installations
Fig. 19 Generally recommended suction pipe installations
7.4 Valves in suction piping
If the pump is operating under static suction lift conditions, a non-
return valve may be installed in the suction pipe to avoid having
to prime the pump each time it is started. The non-return valve
should be of the flap type or a foot-valve.
7.5 Discharge piping
The discharge pipe is usually preceded by a non-return valve and
a discharge isolating valve. The non-return valve protects the
pump against excessive back pressure and reverse rotation of
the pump and prevents back flow through the pump in case of
stoppage or failure of the motor.
If the discharge piping is short, the pipe diameter can be the
same as the discharge port. If the piping is long, the pipe
diameter should be one or two sizes larger than that of the
discharge port. On long horizontal runs, it is desirable to keep the
piping as level as possible.
Avoid high spots, such as loops, as they will collect air and
throttle the system or lead to uneven pumping.
8. Electrical connection
The electrical connections should be carried out by an authorised
electrician in accordance with local regulations.
The operating voltage and frequency are marked on the
nameplate.
Make sure that the motor is suitable for the electricity supply of
the installation site.
The electrical connections should be carried out as shown on the
motor nameplate or in the wiring diagram on the back of the
terminal box cover.
8.1 Frequency converter operation
All three-phase motors can be connected to a frequency
converter.
Frequency converter operation will often expose the motor
insulation system to a heavier load and cause the motor to be
more noisy than usual due to eddy currents caused by voltage
peaks.
In addition, large motors driven via a frequency converter will be
loaded by bearing currents.
When your pump is operated via a frequency converter, check the
following operating conditions:
TM03 2537 4505TM03 2536 4505TM03 2538 4505
Concentric
reducer
Eccentric
reducer
Before removing the terminal box cover and before
any removal/dismantling of the pump, make sure that
the electricity supply has been switched off and that
it cannot be accidentally switched on.
Whenever powered equipment is being used in
explosive surroundings, the rules and regulations
generally or specifically imposed by the relevant
responsible authorities or trade organisations must
be observed.
Operating
conditions Action
2- and 4-pole
motors of 110 kW
and up and 6-pole
motors of 75 kW
and up
Check that one of the motor bearings is
electrically isolated. Contact Grundfos.
Noise critical
applications
Fit a dU/dt filter between the motor and the
frequency converter (reduces the voltage
peaks and thus the noise).
Particularly noise
critical applications
Fit a sinusoidal filter.
Cable length Fit a cable that meets the specifications
laid down by the frequency converter
supplier. (The length of the cable between
motor and frequency converter affects the
motor load).
Supply voltage up
to 500 V
Check that the motor is suitable for
frequency converter operation.
Supply voltage
between 500 V and
690 V
• Fit a dU/dt filter (reduces the voltage
peaks and thus the noise)
or
• check that the motor has reinforced
insulation.
Supply voltage of
690 V and upwards
• Fit a dU/dt filter
and
• check that the motor has reinforced
insulation.