Transformer phasing

mtfallsmikey

I tried to explain this concept to my asst. chief engineer awhile back, after he blew out a control board on a Trane VAV...now, it IS written!

Roland_4

Transformer phasing

Hi All,
I remember this issue was addressed about a month ago but I can't seem to find it. There was a caution to make certain that all 24Volt transformers be properly phased when installing after-market boiler controls. I will be installing a Tekmar 256 and a seperate 24Volt transformer to power it. Does anyone know how to check the phase of the transformer? Thanks,Roland

Unknown

Here it is

Noel

Roland_4

Phasing

Thanks Noel. What I was looking for. Roland.....

zeke

phasing

If you don't have electronics with their attendant noise problems, i.e. electromechanical only, then I personally DO NOT tie the grounds of the low and high voltage circuitry. I "float". 24 volts AC is hardly a shocking condition and if you inadvertently touch the hot ends you won't blow out the low level circuitry, as you would if you common grounded as suggested.
I do not know if this is code, so you may have to check if you do it.

Dave Ackles

REBCO BOILER MOD.# CR76

I am looking for the btu rating on this steel boiler mod. # CR76 REBCO most likely in the 1960s This boiler is not in the Byrley Book. Any help would be appreciated.
THANKS FOR ANY HELP

lee_7

satrt a new thread for your boiler questions, you will get better results.

Glenn Sossin_2

Repco

I think you got the name wrong - could it be Repco. The 76 probably represented the equivalent of the DOE rating or IBR rating. The time frame of the 60's sounds right. I wouldn't bother doing anything with a steel boiler that old other than replacing it. If thats what your doing, I would look at your actual radiation heat load, not the specs of that boiler.