Startup; Direction Of Rotation - Grundfos APG Serie Montage- Und Betriebsanleitung

7.1.2 Moisture sensor
Applies only to APG.50.48, APG.50.65 and
APG.50.92.
Pumps with moisture sensor have a sensor in the oil
chamber between the motor and the pump housing.
Through the separate level relay (No 99010129), the
moisture sensor transmits a signal to the safety
circuit to trip the motor in case of ingress of moisture/
water into the pump. See fig. 4.
A1
B1
18
Fig. 4 Wiring, moisture relay
10
3
15
1
B2 B3 4
R
2
U
16 A2

8. Startup

Proceed as follows:
1. Check the oil level in the oil chamber.
2. Remove the fuses, and check whether the
impeller can rotate freely.
3. Check whether the monitoring units, if used, are
operating satisfactorily.
4. Check whether the system has been filled with
liquid and vented.
5. Make sure that the pump is submerged in the
liquid.
6. Open the isolating valves, if fitted.
7. Check the setting of the level switches.
8. Start the pump.
The pump may be started for a very short
Note
period without being submerged in order to
check the direction of rotation.

8.1 Direction of rotation

All single-phase pumps are factory-set to the correct
direction of rotation.
Before starting up three-phase pumps, check the
direction of rotation. The direction of rotation should
be clockwise when viewed from above. When
starting up, the pump will jerk in the opposite
direction of the direction of rotation. If the direction of
rotation is wrong, interchange two of the three
phases of the power supply.
Checking the direction of rotation
The direction of rotation should be checked every
time the pump is connected to a new installation.
Check the direction of rotation as follows:
1. Start the pump, and check the quantity of water
or the discharge pressure.
2. Stop the pump, and interchange two of the three
phases to the motor.
3. Start the pump, and check the quantity of water
or the discharge pressure.
4. Stop the pump.
5. Compare the results from points 1 and 3. The
phase connection which gives the larger quantity
of water or the higher pressure gives the correct
direction of rotation.