A705-61-880 Issue M
Page 16 © Edwards Limited 2012. All rights reserved.
Edwards and the Edwards logo are trademarks of Edwards Limited.
Installation
3.6.3 Connect the thermistor outputs
The motor windings are fitted with thermistors, which are terminated in the motor terminal-box. You must connect
the thermistor outputs to a suitable control circuit to isolate the electrical supply from the pump-motor and shut
down the pump if the windings overheat.
1. Remove the plug from one of the cable entry holes on the pump-motor terminal box (Figure 1, item 17).
2. Fit a suitable cable gland and nut to the entry hole, then pass your control cable through the cable-gland.
The gland you use must be rated to provide seal protection of IP55 (in IEC 529 or NEMA MG1.pt.5) or better to
the terminal box.
3. Connect the wires in the control cable to the thermistor output terminals in the terminal-box: refer to the motor
manual supplied with your pump or motor nameplate.
4. Tighten the cable-gland nut strain relief screws.
5. Refit and secure the terminal box cover.
3.6.4 Connect to the thermal snap-switches
Ensure that you route the thermal snap-switch cable away from hot surfaces of the pump or other equipment.
If you do not, the cable may be damaged.
Connect the output of the warning thermal snap-switch to your control equipment to provide an indication that the
pump is too hot.
You must connect the output of the shut-down thermal snap-switch to the electrical-overload control-loop of your
contactor, so that the contactor will automatically switch off the pump if it is too hot: refer to Figure 3.
Connect the pump-motor thermistor outputs to a suitable control circuit to isolate the electrical
supply when the pump-motor overheats. If you do not, you can damage the pump and there may
be a risk of fire.
Incorporate a manual reset device in your control equipment. If you do not (and a fault which
causes the thermistors to shut down the pump is not corrected), the pump will automatically
switch on again when the motor windings cool down. If you have started maintenance or fault
finding on the pump, there will be a risk of injury to people.
You must connect the shut-down thermal snap-switch so that the pump stops when the thermal
snap-switch opens. If you do not, there may be a risk of fire or explosion.
Incorporate a manual reset device in your control equipment. If you do not (and a fault which
causes the shut-down thermal snap-switch to open is not corrected), the pump will automatically
switch on again when it cools down. If you have started maintenance or fault finding on the pump,
there will then be a risk of fire or explosion and injury to people.
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