Tjernlund UC1 Universal Control (Version X.06) 8504107 Rev D 07/05 User Manual
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LED STATUS INDICATORS
LED #4 & #5 (Red) Flashing Alternately = Venter in Pre-purge. (Pre-Purge options 0, 5, 20, 35 seconds)
LED #4 & #5 (Red) Flashing in Unison = Venter in Post-Purge. (Post-Purge options 0, 30 seconds or 1, 2, 4, 8, 16 minutes)
LED #4 Flashes Continuously*
= Fan Prover opened for more than 10 seconds during burner cycle.
(Venter will run for 10 minutes, attempting to make Fan Prover)
LLED #5 (Red) Flashing Intermittently
= With no call for heat, flashes 3 seconds on / 3 seconds off if microcontroller is working properly.
LED FAULT INDICATORS
Fault conditions are indicated by counting the number of times LED #4 (Red) flashes.
LED #4 Flashes 2 Times
Fan Prover was in electrically closed position prior to venter operation.
LED #4 Flashes 3 Times*
Fan Prover does not close within 60 seconds after call for heat.
LED #4 Flashes 4 Times*
Fan Prover did not re-close after 10 minutes of Venter operation.
LED #4 Flashes 5 Times*
Fan Prover opened for more than 10 seconds during burner cycle but closed within 10 minutes.
* Investigate cause of Fan Prover short cycling such as; Firing burner at capacities or temperatures exceeding Venter limits,
excessive vent pipe runs, elbows directly on venter discharge,high winds, plugged / kinked Fan Prover sensing tube or a faulty
Fan Prover switch. In-Forcer model’s intake screen and prefilter, if applicable, should be cleaned if necessary.
CHECKING MEMORY FOR LAST FAULT CODE
IMPORTANT: Prior to accessing the fault code memory, note the settings of the dip switches so that they can be returned to their
original Pre / Post-Purge positions. When power is supplied to the UC1 use caution when moving dip switches.
The last fault code can be retrieved at any time by setting all dip switches 1-8 to the up, or “on” position. The last fault code, or
lack there of, will be indicated by counting the number of times LED 4 flashes. By moving any of the dip switches back to their
original position, the fault code will be cleared. NOTE: The UC1 board must have its 115 VAC power supply present when any of
the (1-8) dip switches are moved back to their original position for the fault code to clear.
PRE / POST PURGE AND PROVER STATUS CHECK DIP SWITCH SETTINGS
Remove power to UC1 and heating equipment when installing, servicing or changing dip switch settings. Failure to do so may result in
personal injury and/or equipment damage. LED #6 (RED) should not be on if 115 VAC supply power is removed from the control.
Pre-purge
Used for longer vent runs to get draft fully established throughout the vent system prior to burner ignition. Also beneficial for nega-
tive pressure prone environments. IMPORTANT: Nuisance equipment lockouts may occur if Venter pre-purge is running in con-
junction with and is longer than any equipment timing circuit. Pre-purge settings must be shorter than burner control lockout time
unless wired prior to burner control timing circuit (i.e. aquastat / thermostat).
Post-purge
A Venter post-purge has been factory set at 2 minutes. Confirm that dip switch #5 is in the up or "on" position. Oil fired equipment
requires that the post-purge be long enough to eliminate post cycle nozzle drip odor. A longer post-purge may be necessary for
longer vent runs or high heat retention, refractory lined combustion chambers. A shorter post-purge may be desired for gas installations
or when using the UC1 to control a combustion air In-Forcer.
IMPORTANT: Fault codes will automatically be displayed after a fault condition occurs. If the call for heat interlock signal
or 115 VAC power is removed, the UC1 board will reset and the fault will be stored in memory instead of displayed. Any
new fault will replace any previous fault.
3
Pre-Purge
Post-Purge
Pre-Cycle
Prover Status
Check Activated
DIP SWITCH NUMBERING
1
ON
2
3 4 5 6 7 8
9
POST-PURGE SETTINGS (SEE “POST-PURGE” ABOVE PRIOR TO SETTING)
4
3
4
8
6
5
7
3
5 6 7 8
3 4 5 6 7 8
3
7
5
4
6
8
4
3
4
8
6
5
7
3
5 6 7 8
3 4 5 6 7 8
4 Minutes
8 Minutes
16 Minutes
1 Minute
0 Seconds
30 Seconds
2 Minutes
ON
ON
1 9
LED 1 AMBER
LED 2 BLUE
LED 3 GREEN
LED 4 RED
LED 5 RED
LED 6 RED
POWER LED
ON