Trasformer tripping the secondary control voltage

[valdezjc]

Hello, any body that can send me in the rigth direction, I have a heatpump ICP PFH060H000A that is making the secondary control voltage to trip(transformer is multi-voltage 120/208/230/40Va) when is in heat mode. I have check the defrost card and the sensor to ground looking for any cain of short with out success. Any help will be highly appreciated.

[Mille Racer 69]

What about cooling mode or emergency heat?
If not in emergency heat, check ohms @ contractors, should be somewhere around 8 ohms

[Baycienda]

Since this is posted in tech to tech and not in aop and I need to get my post count up, here you go. Check for a short going from your frost control board to your reversing valve. If you only have low voltage issues in heat try removing the wires from your reversing valve and securing them where they will not short and see if it blows. If it doesn't, it could be the reversing valves solenoid. Try taking a piece of plastic flexible conduit and putting it on your reversing valve wires. If its only tripping on heat, its localized to your O terminal. Some shorts on reversing valve wires can be really small.

[trey r]

Since this is posted in tech to tech and not in aop and I need to get my post count up, here you go. Check for a short going from your frost control board to your reversing valve. If you only have low voltage issues in heat try removing the wires from your reversing valve and securing them where they will not short and see if it blows. If it doesn't, it could be the reversing valves solenoid. Try taking a piece of plastic flexible conduit and putting it on your reversing valve wires. If its only tripping on heat, its localized to your O terminal. Some shorts on reversing valve wires can be really small.

ICP doesn't energize the reversing valve in heat execpt during defrost.

[trey r]

Hello, any body that can send me in the rigth direction, I have a heatpump ICP PFH060H000A that is making the secondary control voltage to trip(transformer is multi-voltage 120/208/230/40Va) when is in heat mode. I have check the defrost card and the sensor to ground looking for any cain of short with out success. Any help will be highly appreciated.

Is this short immediate or intermittent?

[AC5096]

I'd be breaking out the ohm meter. Check resistance of all the energized loads in the heating mode, and inspect the control wiring.

Having a little problem with the OP's comment on the multitap primary Xformer. As long as it's wired for the correct line voltage, it shouldn't be a problem.
Don't think that would figure into the equation.

Correct me if I'm wrong. A RV that energizes in the heat mode is connected to the B terminal.

[ncboston]

I had a Carrier heat pump about a year ago that would trip the lv ckt brkr, but only when coming out of heat. Isolated everything....everything ohm'd good..
Finally found that when the heat cycle ended it tripped because the secondary was grounded.

[Mille Racer 69]

If the reversing valve t state wire is blue then the valve is energized in heating, orange is for cooling.

[platchford]

If the reversing valve t state wire is blue then the valve is energized in heating, orange is for cooling.

If you are referring to the wires from the stat to the outdoor unit, the wire can be any color. Depending on the installer and the number and color of the conductors in the wire they ran they could have used blue for common instead... or anything else they wanted to do.

[DarrinB]

ICP doesn't energize the reversing valve in heat execpt during defrost.

The question in your next post is a great one. On reading the op, I was immediately wondering if this 'short' is happening when the unit goes into defrost.

To the OP, is this shorting out as soon as there is a call for heat, or is the short occurring at some point during the heating cycle? Like, say, when the unit goes to defrost?

[Baycienda]

AC5096 You are right, I apologize. O is used for Ruud, Rheem, and Weather King. ICP products (Heil, Tempstar) are ran off of B. But I do believe that if you break the connection that holds the problem you will find it a lot quicker.

[Williamsma]

AC5096 You are right, I apologize. O is used for Ruud, Rheem, and Weather King. ICP products (Heil, Tempstar) are ran off of B. But I do believe that if you break the connection that holds the problem you will find it a lot quicker.

Ruud/Rheem energizes the rv in heat which is a B terminal, most everbody else energizes the rv in cool which is an O terminal, and trane uses a B terminal for common.

[valdezjc]

I had a Carrier heat pump about a year ago that would trip the lv ckt brkr, but only when coming out of heat. Isolated everything....everything ohm'd good..
Finally found that when the heat cycle ended it tripped because the secondary was grounded.

thank you guys for all the inputs, This unit runs good in heat all the way until set point is satisface, then it will tripp the secondary voltage. I did remember seen one of the leads of the secondary grounded to the chassys of the unit.
Would this be the problem.....?
This morning I when back to this unit and remove the thermostat from the base and check the jumper settings, they were all OK, and when I put the thermostat back the system come back ON and star the heating cycle like nothing happen. I be going back tomorrow and remove the ground wire to the secondary.
Thanks for all the inputs

[atoztech]

I did remember seen one of the leads of the secondary grounded to the chassys of the unit.

As long as its your common on the secondary going to your chassis ground its fine, but make sure its grounded to common. Is this an imediate short on a call for heat or intermittant?

[Mille Racer 69]

If you are referring to the wires from the stat to the outdoor unit, the wire can be any color. Depending on the installer and the number and color of the conductors in the wire they ran they could have used blue for common instead... or anything else they wanted to do.

And it is that installer i am cussing out in my head.
The wires are color coded for a reason.
An installer that does not use the wires as intended
Does not have job security.

[ncboston]

thank you guys for all the inputs, This unit runs good in heat all the way until set point is satisface, then it will tripp the secondary voltage. I did remember seen one of the leads of the secondary grounded to the chassys of the unit.
Would this be the problem.....?
This morning I when back to this unit and remove the thermostat from the base and check the jumper settings, they were all OK, and when I put the thermostat back the system come back ON and star the heating cycle like nothing happen. I be going back tomorrow and remove the ground wire to the secondary.
Thanks for all the inputs

Good Luck.

[airman6290]

If you are tripping the low voltage then you obviously have a short one of the easiest ways to determine which circuit it is in is to isolate each one until it stops tripping. you can do this at the air handler by disconnecting one of the low voltage wires at a time example disconnect the white and cycle it or just use your ampmeter you should be drawing considerably less than 2 amps. If the white isn't the problem try the yellow and agin power up and check amps when you find the problem circuit then check the wiring and any relays in that circuit Darrell

[valdezjc]

Thank you all for your good inputs... i when ahead and replace the defrost card after I was able to recreate the fault.
The fault was cause for the initial call for heat. I should spend more time in trying to recreate the problem...after I replace the board everithing works like a charm.
Thank you again to all!!!

[trey r]

And it is that installer i am cussing out in my head.
The wires are color coded for a reason.
An installer that does not use the wires as intended
Does not have job security.

Why? They are color coded for ease of tracing. For a seasoned tech it is only a pet peeve, not really an issue. I don't know about installers losing their jobs over it.

I had a short in a wall today and used a grey conductor for y.

[bover]

OK, on line voltage to transformer unhooked on one side, big spark or little spark when touch together? Big spark is over 10 amps, will smoke transformer, and indicates a direct short in low voltage wires. Check for goats in back yard (true story).