Preventative Maintenance; Motor Replacement - Grundfos CR Series Installation And Operation Manual

Preventative Maintenance

At regular intervals depending on the conditions and time of operation, the following checks should be made:
1. Pump meets required performance and is operating smoothly and quietly.
2. There are no leaks, particularly at the shaft seal.
3. The motor is not overheating.
4. Remove and clean all strainers or filters in the system.
5. Verify the tripping of the motor overload protection.
6. Check the operation of all controls. Check unit control cycling twice and adjust, if necessary.
7. If the pump is not operated for unusually long periods, the unit should be maintained in accordance with these instructions. In addition,
if the pump is not drained, the pump shaft should be manually rotated or run for short periods of time at monthly intervals.
8. To extend the pump life in severe duty applications, consider performing one of the following actions:
- Drain the pump after each use.
- Flush the pump , through system, with water or other fluid that is compatible with the pump materials and process liquid.
- Disassemble the pump liquid components and thoroughly rinse or wash them with water or other fluid dthat is compatible with the
pump materials and process liquid.
If the pump fails to operate or there is a loss of performance, refer to the Troubleshooting Section on pages 13-14.

Motor Replacement

If the motor is damaged due to bearing failure, burning or electrical failure, the following instructions detail
how to remove the motor for replacement. It must be emphasized that motors used on CR pumps are
specifically selected to our rigid specifications. Replacement motors must be of the same frame size, should
be equipped with the same or better bearings and have the same service factor. Failure to follow these
recommendations may result in premature motor failure.
Disassembly
1. Turn off and lock out power supply. The power supply wiring can not be safely disconnected
from the motor wires.
2. Remove the coupling guards.
3. Using the proper metric Allen wrench, loosen the four cap screws in the coupling. Completely
remove coupling halves. On CR1s-CR20, the shaft pin can be left in the pump shaft. CR(N)32, 45,
64 and 90 do not have a shaft pin.
CR 1s, 1, 3, 5, 10, 15, and 20: do not loosen the three shaft seal securing allen screws.
4. With the correct size wrench, loosen and remove the four bolts which hold the motor to the
pump end.
5. Lift the motor straight up until the shaft has cleared the motor stool.
Assembly
1. Remove key from motor shaft, if present, and discard.
2. Thoroughly clean the surfaces of the motor and pump end mounting flange. The motor and shaft must be clean of all oil/grease and
other contaminants where the coupling attaches. Set the motor on the pump end.
3. Place the terminal box in the desired position by rotating the motor.
4. Insert the mounting bolts, then diagonally and evenly tighten. For 3/8" bolts, torque to 17 ft.-lbs., for 1/2" bolts torque to 30 ft.-lbs., and
for 5/8" bolts torque to 59 ft.-lbs.
5. CR 1s, 1, 3, and 5:
Insert shaft pin into shaft hole. Reinstall the coupling halves onto shaft and shaft pin. Reinstall the coupling screws and leave loose. Check
that the gaps on either side of the coupling are even, and that the motor shaft keyway is centered in the coupling half, as shown in Figure
6a, page 11. Tighten the screws to the correct torque.
CR 10, 15 and 20:
Insert shaft pin into shaft hole. Insert plastic shaft seal spacer beneath shaft seal collar. Reinstall the coupling halves onto shaft and shaft
pin. Reinstall the coupling screws and leave loose. Check that the gaps on either side of the coupling are even and that the motor shaft key
way is centered in the coupling half, as shown in Figure 6a, page 11. Tighten the screws to the correct torque. Remove plastic shaft seal
spacer and hang it on inside of coupling guard.
CR 2, 4, 8 and 16:
Reinstall coupling halves. Make sure the shaft pin is located in the pump shaft. Put the cap screws loosely back into the coupling halves.
Using a large screwdriver, raise the pump shaft by placing the tip of the screwdriver under the coupling and carefully elevating the
coupling to its highest point (see Figure 6). Note: the shaft can only be raised approximately 0.20 inches (5mm). Now lower the shaft
halfway back down the distance you just raised it and tighten the coupling screws (finger tight) while keeping the coupling separation
equal on both sides. When the screws are tight enough to keep the couplings in place, then torque the screws evenly in a criss-cross pattern.
10
Figure 6
CR(X)(N)(T) 8, 16 & CRT 2, 4
• Note the clearance
below the coupling
• Raise the coupling
higher, as far as it
will go.
• Lower it halfway back
down (1/2 the distance
you just raised it).
• Tighten screws
(see torque specifica-
tions below)