Circulator wiring question

[Jim Post]

I replaced the B&G series 100 pump on my existing lp boiler with a Grundfos 3-speed circulator yesterday and ran into some problems when I went to connect the old wiring to the new circulator...

First, the old wire insulator casing was shot...cracked and broken in spots so I am going to replace the wiring from the LP boiler's Honeywell control to the circulator.

Also, the install manual calls for a ground wire but the 40 year old B&G pump was just wired with two white wires and no ground. Is this a problem for wiring the new circulator? Should I run a ground circuit back to Honeywell control on the LP boiler? If so, what can I safely ground to...looking at the control I don't see an obvious ground terminal.

Thanks for any advice you care to share.

jp

 

[Nofossil]

Code would probably require you to have a ground. The idea is that if your hot lead shorted to the case, you want to trip the breaker rather than having the case at 110 volts. Since there are probably several other things grounded to the same plumbing, it's functionally optional. But I didn't say that. Typically you can ground to the metal case of the device and/or the incoming ground wire from the line power connection.

 

[Jim Post]

Thanks Nofo!

 

[sgschwend]

Look for the input power connections for your unit. You should be able to find the ground lead connected to the frame. Connect your ground to this location and you will have a good safe ground. And that is what it is there for.