Newest Threads

**RonRock** · 11-05-2011, 03:52 PM

Sorry for the simple question. But here goes.

I want to control a heating element with my Ranco. The element uses 9.2 Amps. I have looked at the specs of the Ranco and am unsure if a heating element will be used under Normally Open, or Normally Closed. I'm thinking NO, but before I burn up a good Ranco I figured I'd ask.

Ranco specs,

Normally Open (NO): 16 Amps @120Volts
Normally Closed (NC): 8 Amps @120Volts

day_trippr · 11-05-2011, 03:54 PM

Ok, I had to look at my Ranco's instruction sheet 'cuz I've never used the single stage controller for heating.
You definitely want to use the NC points and set the controller mode to Heating...

Cheers!

**Shockerengr** · 11-05-2011, 04:22 PM

Quote:

Originally Posted by day_trippr

Ok, I had to look at my Ranco's instruction sheet 'cuz I've never used the single stage controller for heating.
You definitely want to use the NC points and set the controller mode to Heating...

Cheers!

That's backward.

NO means the contacts are normally open when the control is 'off'
NC means the contacts are normally closed when the control is off

So if you use NC contacts with a heater, on heating mode, when the controller calls for heat it will shut the element off, and when it doesn't it will turn the heater on.

NC is used for 'inverting' logic...i.e. you can use it for heating when the controller is set for cooling and vice versa...but it's not typically used.

For your set up, set the controller to heat, and put the element on the NO contacts.

**microbusbrewery** · 11-05-2011, 04:47 PM

Quote:

Originally Posted by RonRock

Sorry for the simple question. But here goes.

I want to control a heating element with my Ranco. The element uses 9.2 Amps. I have looked at the specs of the Ranco and am unsure if a heating element will be used under Normally Open, or Normally Closed. I'm thinking NO, but before I burn up a good Ranco I figured I'd ask.

Ranco specs,

Normally Open (NO): 16 Amps @120Volts
Normally Closed (NC): 8 Amps @120Volts

+1 for what Shockerengr said, you want to use NO.

Re the amperage, are you sure 9.2 is correct? I'm assuming it's a water heater element. If so the smallest ones I've usually seen are 1500 watts, so 1500w / 120v = 12.5 amps

**RonRock** · 11-05-2011, 05:29 PM

Thanks guys. I'll admit it is somewhat refreshing that there was a bit of confusion between others. Not just me.

Yes I checked the element with my amp meter. Been a while since I assembled it and don't recall exactly what the element was rated at. Seems to me it was a 220V element that I'm running on 120. But I am sure of the amp load, I checked that just before I posted.

Thanks,
Ron

day_trippr · 11-06-2011, 12:18 AM

Quote:

Originally Posted by Shockerengr

That's backward.

You're right - I got caught up in checking the manual and then totally dumb-thumbed that. NO points are the right ones to use.

Cheers!