I need help wiring in my new electric forced air furnace...

[chopsaw]

24 volts is 24 volts . Amp draw from elements does not affect that

 

[bill1]

24 volts is 24 volts . Amp draw from elements does not affect that

I was referring to the VA, volt-amps, or power, of the coil, and whether the transformer had the power to drive it and if the thermostat had appropriate current ratings to handle it. Obviously an 800A contactor has beefier contacts than a 1A relay, so the solenoidal coil that moves them will be sized to require more power.
That said, the HVAC world appears to have settled on a cheap contactor design called Definite Purpose. The case style and mounting feet of the DP Compact models appear to be what Dave has. The leads to the coil are down low on opposite sides, with two (connected) male spades on each side. (Which answers one of my questions.) Although DP Compacts only go to a rated current of 40A, that is for motor loads and the beefiest Eaton C25 is rated for 50A into purely resistive loads, which is what the filaments (elements) present. I'm hoping that's what Dave has.
And looking at Eaton's coil characteristics, they're all 8 VA within that family regardless of contact rating and coil voltage. (On the other hand, the beefier "Special Purpose" contactors of similar switching capabilities have 50 VA coils.)
24VAC appears the standard control voltage in residential HVAC so no surprise there. That looks like about a 12W transformer (need to confirm) so we should be ok, though not a lot of margin. And this stuff all seems to fit together well (it would cost a fortune for the average homeowner to service it otherwise) so most home thermostats can probably handle 1/3-amps of control current to the white wire as well.

 

[daveomak]

I looked up the technical specs on your cooler unit. The bad news is that your unit uses a split phase motor that is not easily subjected to speed control.
JC

It's a heater furnace only... No AC....

 

[daveomak]

What is . "FLA, LRA, & RES"

 

[daveomak]

 

[daveomak]

I'm trying to get the stuff you guys need.... What did I miss ???

 

[daveomak]

Morning again.... it's time to cut hay ... It's waist high... Soooo, I'll be in my outdoor office most of the day...
On SECOND THOUGHT... Where did that come from ???

 

[chopsaw]

What is . "FLA, LRA, & RES"

Full load amps
Locked rotor amps
RES , resistance ( I think ) That's what the coil should read in ohms
Numbers used to trouble shoot the unit I believe .

 

[daveomak]

 

[zwiller]

Is the cabinet/air handler a Goodman MBR1200?

http://igate.northernplumbing.com/manuals/goodman/mbr.pdf

 

[bill1]

Full load amps
Locked rotor amps
RES , resistance ( I think ) That's what the coil should read in ohms
Numbers used to trouble shoot the unit I believe .

Agree with FLA and LRA. I'm pretty sure RES is the constant (on) current rating for a purely resistive load, so 50A, which is sized correctly for 10kW filament-based heaters.
This is a perfect contactor for the job. Let me digest the other stuff after I mow my own hay.

 

[daveomak]

MBR 0800 HKR10

 

[bill1]

daveomak...are you home free on this now or are there still loose ends? Zwiller's link to the 2011 manual I think is closer to what you have than the manual pages you posted earlier (and are now down.)

I've found ~4 different manuals for this covering about a 10 year span so we should have all the info you need. Knowing about how old yours is might be useful...did you inherit it, find a close-out floor model, or ...?

 

[daveomak]

It's purchased new a few months ago....