Wiring a CK-63 Field Controller to a Centennial / Williamson Oil Furnace Model CHB-105-DD-S2

bento · June 3

Hello HVAC experts… I am an engineer trying to wire a newly installed oil forced hot air furnace (Williamson Model CHB-105-DD-S2) as a replacement to my 20 year old oil furnace. My original system included the Field Controls Kit that had previously been installed. This included a SWG power venter, CK-63 controller, and a WMO-1 Safety Switch. I also have a Honeywell EMM3 three zone system that controls the dampers in the HVAC ducting, with three thermostat inputs and. This all works fine.

I connected everything up the way I thought it should. Everything seems to work ok, however, the venter power blower wont turn off when there is no demand for heat, and during purge cycles. I believe I must have wired the T1 or T3 connections on the CK-63 controller wrong.

The new furnace contains a Beckett burner with a Beckett Genisys 7505P 1515 controller. I have reviewed the Williamson furnace, Beckett Genisys controller, and Field Controls wiring schematics, and it is not crystal clear to me how to hook up the T1 and T3 terminals on the CK-63 controller. I see that the T1 terminal needs to be wired to the orange wire on the Beckett controller, and the T3 terminal needs to connect directly to the burner motor thru a WMO-1 Safety Switch , but I am unsure exactly how to do that.

Can someone with experience on these systems tell me exactly what these two wires I need to connect to within the furnace? Any help would be greatly appreciated.

HydronicMike · June 4

Who’s setting up the burner with a full combustion analysis?

bento · June 4

I am going to have the combustion optimized by a contractor after I finish the installation.

EdTheHeaterMan · June 4

If you are comfortable wuth electrical control relays, the instructions are pretty self explanatory. The proper way is to use the proving switch on the CK63 to break the orange wire between the primary control and the burner motor. This keeps the burner from operating if the proving switch fails to indicate there is sufficient draft. Your motor does not operate and the primary control goes off by the safety switch

Let me look at the diagrams for both the furnace and the CK63 to see if there are any peculiarities that need to be addressed.

BRB

EdTheHeaterMan · June 4

The wiringfor your Williamson looks line a normal oil fired furnace. There should be no problems as long as you have this wiring diagram on your furnace. and it still have the original factory wiring without modification.

Let me know if this diagram reflects your system. I will be working on your diagram that you will want to print out and place near your furnace, in a laminated jacket for future reference.

bento · June 4

Thank you Ed. Most kind of you to provide this insight.

I was thinking that I would sever the orange wire connection between the 7505P Beckett controller and the burner motor. Then splice the T1 to the orange wire that goes to the burner motor and splice the T3 to the orange wire lead to the primary control. Does that sound correct?

Let me know if you need help finding the diagrams.

Jack B.

109A_5 · June 4

@EdTheHeaterMan is the expert on things like this.

I would think the CK-63 would be set to 24 VAC operation. The W terminal from the thermostat (24 VAC during a call for heat) to T1 of the CK-63. T2 to the C terminal on the furnace controller. T3 goes to W on the furnace controller. The WMO-1 is connected like in the Red box below.

bento · June 4

Thank you Ed. The CK-63 is already set up for 120V AC, not 24V. So I think I will try to splice the orange wire between the burner controller and the burner motor, which is to be connected to the T1and T3 terminals in the CK-63 board. I will do this tomorrow and let you know how it works. The thermostat connection comes from the three zone Honeywell controller and directly to the burner.

EdTheHeaterMan · June 4

Here is the diagral for your furnace if you have the R8184G

But I now see that you have the electronic primary control

It will take another minute to chang up the diagram.

EdTheHeaterMan · June 4

Here is the Beckett electronic, Honeywell/Resideo Electronic and the Carlin Electronic control diagram

unless your furnace wiring is different. You need to let me know what fan timer control you have or is it the Fan Limit as the diagram I used shows. @109A_5 has located a different wiring diagram hat is not the one I used.

Since this is an oil burner I would prefer to use the 120 VAC circuit. It seems safer. When I learned about Oil Burners in 1970s, the instructor made a point about not using the 24 VAC circuit for limit controls like you can on a gas furnace. It has something to do with tripping a circuit breaker if there is a short circuit. 24 VAC will not trip the breaker It might melt a trandformer but the burner may still operate, if the is the operating limit or safety limit like the proving switch is in the CK63 control connected ti low control volatage. If a black (HOT) wire melts on a high temperature vent pipe that will trip the breaker. If a 24 volt wire melts on a hot stove pipe, that may just let the factory installed smoke out, and make the burner keep operating when it is not supposed to. @109A_5 might call that a short circuit (not a dead short) and the primary control will be stuck in the on position even without the call for heat from the thermostat. Even if the vent motor not operating.

109A_5 · June 4

This should work too.

bento · June 4

Thanks Ed. It’s late here in Massachusetts. I will carefully read everything that provided to me tomorrow.

HeatingHelp.com · June 4

Perhaps @AlanWornham at Beckett can help as well. Thanks!

bento · June 4

Thank you Ed. I wired everything exactly how you suggested and it works perfect now. You are awesome!!!

Wiring a CK-63 Field Controller to a Centennial / Williamson Oil Furnace Model CHB-105-DD-S2

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