Tjernlund DCOP1 Constant Operating Pressure Draft Control 8504174 (Discontinued) - Manual (Page 19)

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If faults exist check PSA-1 Prover P1 & P2 safety circuit. PSA-1 Fan Prover setpoint, DCOP1 draft setpoint or balancing of system
may be required. See “Adjustment of Draft Setpoint, Balancing Baffle(s) and Barometric Draft Control(s)” on page 16.
If no faults exist, with a call for heat established check for 115 VAC across UC1 terminals N and MTR which should be connected
to DCOP1 terminals T6 and T9.
Voltage present: Verify wiring connections between DCOP1 and RT-Series Inducer. Check adjustment pot on DCOP1. Too low of
an adjustment may stall Inducer. Adjust clockwise to see if Inducer speeds up. If Inducer does not speed up and there is 115 VAC
across the T6 and T9 terminals on DCOP1 control, verify that Inducer motor capacitor is good. Disconnect the wire from capacitor
that is connected to the ORG Motor terminal on DCOP1 control. Reconnect Orange wire from Inducer capacitor in 4 x 4 electrical
box to the Orange wire that should be capped off coming from RT-Series Inducer whip. Remove the Red and White/Red leads that
were connected to the MOTOR RED and WHT/RED connection on DCOP1 and provide 115 VAC to them. If motor runs, replace
COP control circuit board part number 950-8805. If motor does not run, verify capacitor is good. Replace RT-Series Inducer
capacitor or motor if necessary.
No voltage present: Replace UC1 circuit board part number 950-8804.
SYMPTOM 3: INDUCER OPERATES, BUT BURNER DOES NOT
For any newly established call for heat the Inducer will run for 60 seconds to try to close the UC1 Fan Prover circuit (P1 to P2). If
circuit can not be made within 60 seconds LED #4 (Red) will flash 3 times, indicating a prover check circuit fault on UC1 start up.
NOTE: The UC1 safety circuit and LED #4 (Red) will be reset if the call for heat interlock signal or 115 VAC power is removed. If
the fan prover makes on start up, but breaks for more than 10 seconds during the burner cycle, LED #4 will flash continuously indi-
cating a prover circuit fault. The Inducer will continue to run for 10 minutes to try to make the prover circuit as long as a call for
heat exists. If Prover does not make within 10 minutes, the UC1 will shut down and LED #4 (Red) will flash 4 times indicating a
prover circuit fault. Remove the call for heat and then reestablish to reset the UC1 prover safety circuit (P1 to P2) & LED #4 (Red).
Verify that LED #2 (Blue) is lit.
Yes, LED #2 (Blue) is lit: Verify that "call jumper" is connected from J1 to J2 on UC1 circuit board if using typical wiring where sup-
ply voltage from terminal 1 is routed to terminal 3 through “call jumper” then to 4 when appliance interlock relay makes. With call
for heat established, verify that wiring is correct by measuring voltage between terminals 1 & 2 and 2 & 4 of UC1 terminal strip.
Voltage should be the same in both cases, if not rewire per appropriate diagram or confirm burner control(s) are functioning prop-
erly. NOTE: If outside power source is provided to terminal 3 and switched to terminal 4 check for continuity between 3 and 4
with leads disconnected from 3 and 4 and Inducer operating. If there is no continuity between 3 and 4 and the Blue LED is lit,
replace UC1 circuit board part number 950-8804. If continuity is present, recheck interlock wiring and burner control(s). If using the
A-B dry contacts for millivolt installations make sure system Linear Limit Spillage switch on draft hood/diverter has not tripped.
Reset if necessary.
No, LED #2 (Blue) is not lit: Remove power from UC1 and confirm dip switch #9 is up or “on” to deactivate the Pre-Cycle Fan
Prover status check. Keeping the Pre-Cycle Prover Status Check activated may cause nuisance lockouts. Remove P1 and P2
prover leads off of PSA-1 Fan Prover switch and jumper together. Reestablish power and call for heat. After 5 second factory set
Inducer pre-purge (Adjustable from 0 to 35 seconds), LED #2 (Blue) should light.
No, LED #2 (Blue) does not light: Replace UC1 circuit board, part number 950-8804.
Yes, LED #2 (Blue) lights up: The PSA-1 Fan Proving switch may not be closing, wiring connections are incorrect/broken or burner
control(s) are not functioning properly. With Inducer running, verify that Inducer performance is sufficient to close Fan Prover con-
tacts by checking for continuity across switch. Replace PSA-1 Fan Prover leads from P1 and P2 back on Fan Proving switch.
No, continuity is not present: Confirm that burner is not firing at capacities or temperatures exceeding Inducer limits. Check for
excessive vent pipe runs, high winds, plugged / kinked Fan Prover sensing tube or a faulty Fan Prover switch. Perform
“Adjustment of Draft Set Point, Balancing Baffles(s) and Barometric Draft Controls” procedure on page 16 to verify if set point
adjustment is necessary on the DCOP1 or PSA-1 Fan Prover. If everything checks out okay, replace PSA-1 Fan Prover.
Yes, continuity present: Recheck interlock wiring and burner control(s).
HOW TO OBTAIN SERVICE ASSISTANCE
1. If you have any questions about your DCOP1 or if it requires adjustment or repair, we suggest that you contact your installer,
contractor or service agency.
2. If you require technical information contact Tjernlund Products, Inc. at 1-800-255-4208 with the following information.
1. Model of the Inducer that DCOP1 is interlocked with as shown on the label attached to Inducer.
2. Name and address of installer and any service agency who performed work on the system.
3. Date of original installation and dates any service work was performed.
4. Details of the problem as you can best describe them.
LIMITED PARTS WARRANTY AND CLAIM PROCEDURE
Tjernlund Products, Inc. warrants the components of the DCOP1 for one year from date of installation. This warranty covers
defects in material and workmanship. This warranty does not cover normal maintenance, transportation or installation charges for
replacement parts or any other service calls or repairs. This warranty DOES NOT cover the complete DCOP1 if it is operative,
except for the defective part.