Tjernlund UCRT Rooftop Inducer Universal Control (Version X.06) 8504162 Rev A 05/11 - Manual (Page 6)

All wiring from the UC1 to the appliance must be appropriate Class 1 wiring as follows: installed in rigid metal conduit, intermediate
metal conduit, rigid non-metallic conduit, electrical metallic tubing, Type MI Cable, Type MC Cable, or be otherwise suitably protected
from physical damage.
SEQUENCE OF OPERATION WITH UC1 UNIVERSAL CONTROL AND 24 VAC OR 115 VAC HEATER CONTROL CIRCUIT:
Control signal from thermostat, aquastat, primary control or gas valve is intercepted and routed to terminal “1” on UC1 terminal
strip. When terminal “1” is energized with either 24 VAC or 115 VAC, the Inducer motor is energized. After draft is established,
the Fan Proving Switch closes within 5 to 10 seconds energizing terminal “4”, which completes the circuit allowing burner to fire.
NOTE: If an Inducer pre-purge is selected, the burner will not fire until the pre-purge time is finished. The Inducer will continue to
run after the burner has finished firing for the set post-purge time cycle. The UC1 is set for a 2 minute post-purge time period from
the factory. See “Pre / Post-Purge Settings” on page 3 for details.
The "1" input terminal on the UC1 can accept either a 24 VAC or 115 VAC control signal. IMPORTANT: The RED voltage
jumper must be positioned based on appliance interlock voltage 24V or 115V. If using the “DRY” contact activation method, use
terminals A & B on UC1 control and position the RED voltage jumper tab in the “DRY” position. See millivolt appliance interlock
diagram for further information. IMPORTANT: Only one interlock method (i.e. 24V, 115V or “Dry”) can be used with the UC1.
Multiple appliance interlocks require the use of our MAC-Series multiple appliance controls.
The steps listed under each diagram are intended as a supplement to the diagram. Wiring colors or designations may vary by
manufacturer. If you are unable to wire the UC1 as outlined in these instructions, call Tjernlund’s Customer Service Department
toll free at 1-800-255-4208 for assistance.
IMPORTANT: If the call for heat interlock signal or 115 VAC power is removed, the UC1 board will reset and any fault, if present,
will be stored in memory instead of displayed. See page 3, “Checking Memory for Last Fault Code”.
UCRT UNIVERSAL CONTROL WIRING SCHEMATIC (UC1 WITH SPEED CONTROL)
IMPORTANT: MORE THAN ONE INTERLOCK METHOD MAY BE APPLICABLE
In many cases it is easier to interlock with the thermostat/aquastat portion of the heater control circuit vs. the ignition module /
primary control portion of the heater control circuit. Review all of the wiring diagram options prior to choosing the best method.
5
INTERCEPTED
CALL FOR
LE
D PO
WE
R
RED
DRY 24V 115V
1 - 2
PRE-PURGE SETTINGS
3 - 8
9
OPEN PROVER OPTION
POST-PURGE SETTINGS
RELAY MTR
NO
SUPPLY
50/60 Hz
115 VAC
INC.
9183006
TJ
E
RNL
UND
P
R
O
DUCTS
,
R
NEUTRAL
LINE / HOT
APPROVED CALL
COMMON /
OR
HEAT
"DRY"
XL
K2
MOTOR
COM
M
N
XN
NO
INTERLOCK
RELAY
J1 COM
J2
JUMPER
CALL
GRE
E
N
RED RED AM
BE
R
BL
UE
FIGURE 1303241RS 5/10/11
MAC1E OR MAC4E
PSA-1 FAN
DEVICES. DO NOT
CONNECT POWER
WILL DAMAGE THE
OR F. DOING SO
TO P1, P2, C, GND
FOR TJERNLUND
GN
D 8
9
F
CONTROL.
AUXILIARY
34
26
7
5
C
1
P1
ON
P2
24 OR 115 VAC
APPROVED CALL BACK TO HEATER
INTERCEPTED CALL COMMON OR NEUTRAL
24 OR 115 VAC INTERCEPTED CALL FOR HEAT
AS APPLIANCE INTERLOCK VOLTAGE.
RED JUMPER POSITION MUST BE THE SAME
5 VDC BOARD-GENERATED POWER
DO NOT SUPPLY POWER!
CALL SWITCH
USER-PROVIDED
DO NOT SUPPLY VOLTAGE
TO "A" OR "B".
115 VAC
LEGEND:
IMPORTANT:
LED LED LED LED LED
TERMINAL 2:
TERMINAL 1:
TERMINAL 4:
LED
TO INDUCER WHITE LEAD AND WHITE/RED LEAD
TO INDUCER BLACK LEAD
OFF
6 AMPS MAX TO INDUCER RED LEAD
ON LOW
HIGH
SPEED CONTROL
ON
3 5 4 2 1 6
PROVER
BLACK
WHITE
RED RED
YELLOW
BLUE
WARNING: Disconnect power supply from the UC1 and heating equipment when making wiring connections and servicing the
Inducer. Failure to do so may result in personal injury and/or equipment damage. LED #6 (RED) should be off with
power removed.