oil gun problem

[lmathews]

Hello,
I have a carlin 701crd oil gun 4 years old. I started having an issue halfway through this past season. At no specific time it would happen.
I would be boiling for maybe 2 hours and sometimes on start up going from low fire to high fire my circuit breaker would trip . when I turn the breaker back on the primary control was burned up and would go through pre purge and attemt to go through the fire setting not light and go into lock out mode. it is not the eye. I have been through 5 primary controls so cant believe they are all defective. currently have the motor at local shop checking brushes and windings but do not think that is the problem. Anyone out there ever have this problem? Carlin techs are baffled and can not tell me.
Thanks Lee

[huck 1]

Have the electrical checked for low voltage ,loose or joints ,weak breaker

[lmathews]

Picked motor up today,no problems with it.

I have checked all connections and changed breaker. Seems to happen when high fire is involved. High fire timer blower damper contactor problem?

[Brian]

It could be the oil valve on the high side. I by passed the primary control on mine years ago, I have an on and off switch.It could be the air damper is stuck and not opening. I believe the air damper has to open then it goes to high fire.

[Brian]

Air damper control is what I should have said.

[Sunday Rock Maple]

Perhaps the arch insulation isn't sufficient and the controller is seeing too high temperature (I think the manual says 140 degrees Fahrenheit is a maximum)? Other than that I would try to verify that there's a s tree stable line voltage (for example, if an RO is running at the same time is everything still ok?)

[WMF]

I would start by getting wiring diagram of the primary control that is on the burner. There are several different ones used on a 701. Find out what exactly is "burned up" on the controllers.
If the output relay on the controller is burning a contact there is too much current for the contact.
I have seen some Carlin 701's with a separate heavy duty contactor just for the motor and I have seen some that power the motor through just the primary control and these ones are pushing the limits of the tiny relay that is in the primary control.
Yours may be wired so more than just the motor is drawing current through the primary control relay such as the damper control and the fuel solenoids.
The main blower motor is an AC motor and has no brushes. The blower motor will draw more amps as the damper motor opens and more air flows through burner.
Get a good clamp on ammeter and see if currents are close to the max limits of primary controller.
Post pics of burner and or model number of primary controller for more help.
I have a Carlin 701 in great shape for sale in the classifieds if things get critical.

[lmathews]

There are separate contactors for motor and air damper control. When primary is burned up it is the circuit that turns on the oil solenoids.

[lmathews]

I am not sure how to attach photos.

[Brian]

Take the cover off the box by the high fire switch and see if there is a bare spot on a wire there. Or maybe there is a short in the high fire oil valve. It sounds like a short is killing the primary control and or tripping your breaker.

[lmathews]

Problem solved! great to know it was a factory problem. It was in the wiring harness were the technicians put in a poor splice job and it melted the wires together.
Thank you all.