Motor starting from lighting switch

[sweet212]

Evening all.

My client has asked me to look into connecting a pump for their garden pond. The existing set up had a DOL starter positioned on a wall in the kitchen from which the pump was operated. (DOL starter now removed)

The new scenario is to turn the pump on via a switch in the 6 gang light switch arrangement. The pump will be over 0.37KW (probably around 0.8KW or so) so will need overload protection.

Could I run the control wiring through the light switch and back to a relay inside a box which would also house the overload protection?

Another option would be to install overload protection nearer the motor.

All single phase.

Any thoughts appreciated.

Many thanks.

 

[brianmoooore]

Assuming the pump is a self contained design, and not something involving pulleys and vee belts, then there is no danger from the motor starting unexpectedly, other than someone getting wet, so NVR is not required.

 

[Deuce]

What hp is the motor, less than 0.50 is does not require overload protection.

0.8 kw = approx 1hp. The limit for no OL protection is indeed 1/2hp

I assume this is an above ground pump? I would use a DOL module and if remote switching is required, use a suitable relay to carry out the on/off switching of the DOL module, in the same enclosure. I wouldn't switch power directly on the supply or load side of the DOL.

NVR not really required as there is no mechanical danger to be protected from if a surprise restart occurs. That said, if you/customer feel strongly enough about it, it's not at all difficult or expensive to build in NVR functionality. For the same reason, you shouldn't need a visible/accessible e-stop button (to the best of my knowledge).

To demonstrate how little of a concern NVR is for a pump, consider that submersible pumps that are sold with a household 3 pin plug are sold up to 1.5kw, and feature only basic thermal overload protection. such pumps are of course switched simply by... erm.. a switch

 

[Deuce]

Sorry I just realised I kept typing DOL in the enclosure, I meant the overload module.

However, just had a quick google and this seems to do all you need, it is configured for remote control too: https://docs-emea.rs-online.com/webdocs/1586/0900766b81586128.pdf