R8845U UNIVERSAL SWITCHING RELAY
68-0215—02
4
Fig. 2. R8845U Internal schematic and typical hookup.
Fig. 3. R8845U schematic diagram for multizone, hydronic
heating system (applies for any number of additional zones).
Fig. 4. R8845U hookup for L7124A/L8124A in an oil-fired, tankless hot water, zoned, pump system.
L1
HOT
L2
R(T) W(T)
C
L2
L1
N.O.
COM
1
1
TO
POWER
LOW VOLTAGE (CLASS 2)
2-WIRE THERMOSTAT
CALL FOR HEAT LED
POWER SUPPLY. PROVIDE OVERLOAD PROTECTION
AND DISCONNECT MEANS AS REQUIRED.
M14294
B
A
X2
X1
LOAD 1
RELAY
LED
TO
POWER
LOAD 2
LOW-VOLTAGE
POWERPILE®
1
1
G
AUTOMOTIVE
FUSE
L1
HOT
L2
2
L
W(T)
L
R(T)
1
B
A
1
1
R8845U RELAY
POWER SUPPLY. PROVIDE OVERLOAD PROTECTION
AND DISCONNECT MEANS AS REQUIRED.
IF CONTROLLING TWO LOADS, USE:
N.O. AND COM FOR LINE VOLTAGE LOAD,
A AND B FOR LINE OR LOW VOLTAGE LOAD.
IF USING LOW VOLTAGE, USE A SEPARATE TRANSFORMER.
M14296
T
T
THERMOSTAT
ZONE 1
ZC
ZP
B1
B2
C1
C2
1
2
BURNER
CIRC.
LINE
THERM.
BURNER
CONTROL
CIRCULATOR
ZONE 1
2
3
THERMOSTAT
ZONE 2
CIRCULATOR
ZONE 2
TO ADDITIONAL R8845U
RELAYS FOR OTHER ZONES
HYDRONIC HEATING
CONTROL TERMINALS
2
3
N.O.
COM
L1
(HOT)
L2
1
2
3
POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED.
CONTROL CASE MUST BE CONNECTED TO EARTH GROUND. USE GROUNDING SCREW PROVIDED.
B1 IS 1/4 IN. TAB TERMINAL.
L2
L1 C1 C2 B2
ZR
ZC
B1
M14298
3
2
BURNER
AND
IGNITION
L7124A, L8124A
G
T
T
F
F
T87F
N.O.
B
A
COM
L2
L1
W(T)
R(T)
N.O.
B
A
COM
L2
L1
W(T)
R(T)
T87F
R8845U RELAY
R8184
T87F
R8845U RELAY
PUMP
PUMP
PUMP
BLACK
WHITE
ORANGE
C554
1
W(T)
R(T)
