Code question for the sparkies
 

I have a boiler installation where my main circulators are 208v, but my pump sequencer only switches a single pole. The instructions note to switch one hot supply, I am concerned that this would still leave a hot supply live in the pump despite it not being turned on creating a potential safety hazard. Does code require that both legs be switched? Should I install DPDT relay's switched by the pump sequencer?

I know its a good idea, my main question is whether it is mandatory.

What you're going to want to do is clean the thermocouple with some steel wool... (lol)
I hope you get a good answer here, this forum owes you for all the answers you give out for free.

Check for a pilot light. If you don't see one, change the air filter and replace the thermostat. . .

You can not leave 1 leg live. How would you lock it out?

2 pole switch rated 120/240
Don't let them sell you a 4 way switch as they are mistaken easily.

The pump should have local isolation for it to be worked on (double pole switch). But for control of the pump cicuit switching one leg is ok, its the same as a 208v baseboard heater only one leg is switched by the inbuilt thermostat.

Jason

Got a lesson on this on a 3/4 hp jet pump with only one leg switched near the pump. The thing was still live on one leg.

EWEL sold a proper switch as described for $28 that shut off both legs. I marked it with my label maker so there was no mistake that both poles were switched off.

Drewski

As some of the other guys mentioned, switching one leg is fine for control but you will need a separate 2 pole switch with lock off to isolate it for maintenance.

Thanks guys, some DPDT switches will certainly be cheaper than relays. I don't want to be 'that guy' who endangers some other tech down the line. I was expecting the pump sequencer control to have DPDT relays.

Caber... you keep referring to DPDT (relay, switch),
but in this case all you need is DPST.

^^ This is what I am picturing as well for a simple disconnect. Double Throw (2 Phase)-Single Throw (One Switch) for a setup that allows everything to be shut down and isolated for maintenance.

Fixed the typo for you.

I think I was just using incorrect terminology, but meaning DPST in terms of a switch. My acronym soup had too many D's.

Unless the code has changed, the electrician wired all my 220v circuits with single pole switches many years back. Shut them off at the breaker for any service work.

LOL, Ah Yes, some times the fingers type faster than the mind thinks. Thanks for that FCL

It would be good to have isolation switch near the boilers have saw 240 volt control wiring in ac unit before the same as you have now.

http://www.nationalpost.com/m/wp/new...bathroom-floor

just so u no.

That example wouldn't apply to me, whenever I heat someone's floor its using warm water that generally isn't even exceeding 95 Fahrenheit, 9 degrees lower than most people's hot tubs. I've never put in an electrical floor heat mat as its not within the scope of work that I pursue.