Weil-McLain WMR-21 - Manual (Page 4)

WMR Switching Relays
4 Part Number 550-141-859/0799
Electrical shock hazard —
Disconnect power before
installing or servicing. Can
cause severe personal injury,
death or substantial property
damage if ignored.
All wiring must be installed in
accordance with:
U.S.A. — National Electrical
Code and any other
national, state or local code
requirements. Wiring must
be N.E.C. Class 1.
Canada — C.S.A. C22.1
Canadian Electrical Code
Part 1 and any other
national, provincial or local
code requirements. Wiring
must be C.S.A. C22.1 C.E.C.
Part 1.
WMR-21 — Typical application
Add circulator to L8124A or C
aquastat/relay
WMR-21 and WMR-22
General wiring
85907
24 VAC
120 VAC
C C
L2 L2 L1 L1 3 3 4 4 5 5 6 6
T
R T
R T
W
T
W
Thermostat or
isolated contact
to activate relay
L8124A or C
Aquastat/relay
Circulator 1
Circulator 2
To burner control
24 vac to 3-wire
thermostat
WMR-21
120 VAC
120 VAC
Hot
Neutral
Hot
Neutral
T
T
ZR
ZC
B1
B2
C1
C2
1
2
Ground
Ground
screw
85905
24 VAC
120 VAC
C C
L2 L2 L1 L1 4 4 5 5 6 6
Thermostat or
isolated contact
to activate relay
Nor
mally open contact out
Nor
mally open contact out
Remove factory-
installed jumper from
L1 to 3 to use 3–4
as isolated contacts.
24 vac to 3-wire
thermostat
WMR-21
120 VAC
Hot
Neutral
Ground
Ground
screw
3 3
85906
24 VAC
120 VAC
C C 5 5 6
NO
6
NO
4
NO
4
NO
6
NC
6
NC
4
NC
4
NC
L2 L2 L1 L1 3 3
T
R T
R T
W
T
W
Common
Thermostat or
isolated contact
to activate relay
Remove factory-
installed jumper from
L1 to 3 to use 3/4/4
as isolated contacts.
Common
24 v
ac to 3-wire
ther
mostat
Nor
mally open
Nor
mally open
Nor
mally closed
Nor
mally closed 120 VAC
Hot
Neutral
WMR-22
Ground
Ground
screw
120 VAC field wiring
120 VAC factory wiring
120 VAC ground lead 24 VAC field wiring
24 VAC factory wiring
Legend
T
R T
R T
W
T
W