replacement transformer

adambnyc

Hey All,

Having an electrical problem with my boiler burning out the transformer. The boiler currently uses this:

http://www.supplyhouse.com/Burnham-80160186-Transformer-50VA-for-IN3-IN12-Boilers

I'd like to use a re-settable transformer, as I have already burned two out. Could i use this in its place?

https://www.amazon.com/Honeywell-AT150F1022-Circuit-Breaker-Transformer/dp/B009PARVXU

The existing transformer is 4 wire, the one i would like to get is 5 or 6 wire.

thanks.

Ironman

As long as it has the same or higher VA rating, it's fine.

You've got a short somewhere which needs to be found and corrected. It could be in a control.

adambnyc

Thank you. I think i know where the short is but dont want to risk another 55 bucks on burning out another transformer. Would i just connect the color coded wires like normal and leave the extra wires coming from the transformer capped?

ChrisJ

Use the taps for the voltage you're inputting and wire nut the ones you don't.

I'd also find out what's drawing all that current first. A circuit breaker isn't a trouble shooting device an ohm meter is.

From what I can tell, for 120V you'll use the black and white wires. Wire nut the others. Double check me though in case I made a mistake.

http://s3.supplyhouse.com/product_files/AT150F1022-Submittal Sheet.pdf

Tim McElwain

If you get in touch with me at gastc@cox.net I will e-mail you a procedure for finding the short. One quick way once you install the circuit breaker transformer (AT-150F-1022) is to disconnect the wires from the gas valve and connect the multimeter to those wires and bring the unit on, if you do not trip the breaker on the transformer then the problem is the gas valve. If you do trip it the problem is in the wiring.

I would need to know what you have for equipment to be able to tell you how to wire the AT150, in most cases however you connect 120 hot to the black wire and neutral to the white wire. The blue and yellow wire are the 24 volt secondary. The remaining orange and red wire can be individually capped off with a wire nut or tape.

Steamhead

You can mount that transformer on a standard 4x4 box cover that has a knockout hole punched in it, and it will fit right where the old one did.

adambnyc

Thanks again! I suspect it's the thermostat wire. I had another issue that I figured out but in order to get the boiler to fire without going to the thermostat, I stripped/crossed the wires. This all worked fine until I taped those wires back up. I'm going to cut out that length and rerun it.

And thank you for the wiring overview, I have a burnham independence gas steam. Everything pretty much standard with the addition of an auto fill.

ChrisJ

Just a tip, if you end up pulling a new wire don't go with bare minimum. Pull a 6 or 8 conductor.

Absolute minimum do 4 but some Cat 5E or CAT 6 is nice and easy to find and both are 8 conductor.

adambnyc

Good advice. Got a lot of cat6 around.

ChrisJ

adambnyc said:

Good advice. Got a lot of cat6 around.

Am I the only one that hates working with that stuff?
For actual ethernet, that is. Seems like it's 100X harder to deal with than CAT 5 and 5E

adambnyc

A bit harder to make turns especially if your using plenum cable. I'm a computer/networking engineer, so I'm pretty used to it. I used to own a structured cabling company as well.

ChrisJ

adambnyc said:

A bit harder to make turns especially if your using plenum cable. I'm a computer/networking engineer, so I'm pretty used to it. I used to own a structured cabling company as well.

I meant regarding making your ends.
Dealing with the spline, and the thicker conductors, and that stupid spreader bar etc.

adambnyc

nah, never had a problem with that. But i've been using one of these for years:

https://www.amazon.com/Platinum-Tools-100054C-Clamshell-EZ-RJPRO/dp/B00939KFOU/ref=sr_1_9?ie=UTF8&qid=1473442932&sr=8-9&keywords=cat5+crimper

You pull the wires thru the end. Makes it easier

ChrisJ

adambnyc said:

nah, never had a problem with that. But i've been using one of these for years:

https://www.amazon.com/Platinum-Tools-100054C-Clamshell-EZ-RJPRO/dp/B00939KFOU/ref=sr_1_9?ie=UTF8&qid=1473442932&sr=8-9&keywords=cat5+crimper

You pull the wires thru the end. Makes it easier

Ah I could never justify that, I only do stuff for my self and friends. My first job in high school was running CAT5 back in the 90s, but since then I only do it when I need to

I use this :

https://www.amazon.com/Klein-Tools-VDV226-011-SEN-Ratcheting-Stripper/dp/B002D3B97U/ref=sr_1_3?ie=UTF8&qid=1473443165&sr=8-3&keywords=rj45+crimp


Good memories, pulling CAT5 through schools etc. Only thing that stunk was our CAT5 had 4 white wires, no stripes so you had to keep track of them as you put them in order. That was a pain. I want to say it was Verizon brand wire, and expensive back then but I can't remember. It's been too long.

adambnyc

its definitely one of those "time vs money" or "time is money" tools. Kinda like I would never own a Ridgid 300/700 but i've got a manual rigid 12D setup. Difference between doing it for a living or for self/friends/hobby

ChrisJ

adambnyc said:

its definitely one of those "time vs money" or "time is money" tools. Kinda like I would never own a Ridgid 300/700 but i've got a manual rigid 12D setup. Difference between doing it for a living or for self/friends/hobby

Yep, exactly.

SWEI

The 23ga Cat6 is nice for long POE runs, but we still use Cat5e for 90% of the stuff we do. Anything faster we generally use glass

adambnyc

The max run on copper is 328 feet. I never really like getting too close to that number especially for POE. Another switch, multimode or single if it's a real long run.

I'll use CAT6 in the data center and Cat5e on the floors unless the customer really feels like paying for CAT6. But with wifi just getting better and better the only real networking is gonna happen in the DC. Pretty much sums up why I don't have the network cabling business anymore.

ChrisJ

I posted this on FB a few days ago as an "age test", which got argued over, because apparently it's not a good "age test".

But whatever. I was pleased several of my friends knew what it was and how to identify it.

ChrisJ

Actually, guys I just realized I ran a lot of CAT5E for sensors and such, but used 18-4 for my thermostat.

Will CAT6 carry enough current for most HVAC systems?
I don't want to give anyone bad advise here, especially when it comes to pulling wire through walls etc.

adambnyc

10/100 but I'm not sure if it's a hub or switch. That's right about the time that both were out there quite a bit. Everything today is a switch, hubs are long dead.

SWEI

I was about to mention that 18-20ga is generally specified, and probably a good idea for anyone wanting to power a WiFi thermostat.

Age test? Try ThickNet Viper Taps, AUI's and (later) 100BaseVG?

ChrisJ

adambnyc said:

10/100 but I'm not sure if it's a hub or switch. That's right about the time that both were out there quite a bit. Everything today is a switch, hubs are long dead.

It's a hub.
You can tell by the collision lights.

adambnyc

Your right! It's been awhile since I've seen one. Quick question about the transformer,

Can someone recommend a more cost effective replacement than the original? I'm not sure I wanna use the trip protected transformer as a permanent solution.

ChrisJ

adambnyc said:

Your right! It's been awhile since I've seen one. Quick question about the transformer,



Can someone recommend a more cost effective replacement than the original? I'm not sure I wanna use the trip protected transformer as a permanent solution.

Any of those Honeywell transformers will work as long as it's 50VA or so, 24V out and 120V in.

The protected one is fine as well, you should never get close to tripping the breaker unless something is really wrong.

BobC

A single #23 wire is good for about 5a max, it has about 2 ohms per 100ft so if the wire were 50 ft long (50ft each side) then the voltage drop would be 10v - a little high.

If you used 2 #23's for each wire (equalls a #20 wire) the resistance would be about half as much so your drop would be 5v, still a bit high. usually you want 10% drop or less.

The resistance drops in half if you go down 3 wire sizes. Now if your only drawing an amp then it would be fine.

http://www.powerstream.com/Wire_Size.htm

Bob

ChrisJ

BobC said:

A single #23 wire is good for about 5a max, it has about 2 ohms per 100ft so if the wire were 50 ft long (50ft each side) then the voltage drop would be 10v - a little high.

If you used 2 #23's for each wire (equalls a #20 wire) the resistance would be about half as much so your drop would be 5v, still a bit high. usually you want 10% drop or less.

The resistance drops in half if you go down 3 wire sizes. Now if your only drawing an amp then it would be fine.

http://www.powerstream.com/Wire_Size.htm

Bob

Last time I measured my steamer it used about 0.5A I think but it's been a long time. That was when I was trying to set the anticipator on a thermostat in late 2011. I remember 12 watts for some reason.

Tim McElwain

The setting for the thermostat should match the amperage draw of the primary control. ( the control it is directly controlling relay, gas valve, zone valve etc.)

Or use an amp meter to find out what your amperage draw is.

Use only a minimum size of 18 gauge wire. All other wire 20, 22, 24 is classified communication wire.

adambnyc

Just a follow up. It was the thermostat wires shorting the system. Thanks to all for the help. Boiler is now 100%