Wiring Guide

2
SR501-4 Switching Relay Wiring
TYPICAL WIRING
(COLD START)
ONE ZONE
SWITCHING RELAY
SR 501-4
FUSE
6 AMP
POWER
ZONE 1
LED
INDICATORS
FUSE
6 AMP
NH3 4 4 566
N/O N/ON/C N/CCOM COM
120 VAC
INPUT
TT
COM
R
W
24
VAC
TO: 120 VAC POWER
CIRCULATOR
JUMPER
TO: TT ON
BOILER
THERMOSTAT
TO: 120 VAC POWER
CIRCULATOR
TO: ZC
TO: ZR
ALTERNATIVE WIRING
(TANKLESS COIL)
ONE ZONE
SWITCHING RELAY
SR 501-4
FUSE
6 AMP
POWER
ZONE 1
LED
INDICATORS
FUSE
6 AMP
NH3 4 4 566
N/O N/ON/C N/CCOM COM
120 VAC
INPUT
TT
COM
R
W
24
VAC
THERMOSTAT
TO: 120 VAC POWER
CIRCULATOR
TO: TT ON BOILER
ALTERNATIVE WIRING
(24 VAC POWERED INPUT SIGNAL)
N
H
REMOVE JUMPER.
DO NOT CONNECT POWER
TO N AND H TERMINALS.
* T STAT LIGHT WILL GO
ON AND OFF WITH 24 VAC
SIGNAL. POWER LIGHT
WILL ALWAYS BE OFF.
ONE ZONE
SWITCHING RELAY
SR 501-4
FUSE
6 AMP
POWER *
ZONE 1 *
LED
INDICATORS
FUSE
6 AMP
NH3 4 4 566
N/O N/ON/C N/CCOM COM
120 VAC
INPUT
TT
COM
R
W
24
VAC
24 VAC
SIGNAL
Note: When using Alternative Wiring diagram, the boiler oper-
ating control’s ZC terminal will see the load of the circulator(s).
Warning: When using Alternative Wiring diagram, wiring
instructions must be followed so power originates from the boiler
aquastat. Failure to follow these wiring instructions may result in
a secondary source of power being connected to the boiler that
may activate it under certain circumstances, causing injury or death.