WMR Switching Relays
2Part Number 550-141-859/0799
Contents Hazard definitions and “To the installer” .............................................................. 2
Specifications and replacement parts ................................................................... 2
WMR-21 layout, schematic diagram and cross reference table ......................... 3
WMR-22 layout, schematic diagram and cross reference table ......................... 3
WMR-21 and WMR-22 General wiring .................................................................. 4
WMR-21 Typical application wiring ..................................................................... 4
Replacement parts
Hazard definitions Indicates presence of hazards that will cause severe personal injury, death
or substantial property damage.
Indicates presence of hazards that can cause severe personal injury, death
or substantial property damage.
Indicates presence of hazards that will or can cause minor personal injury
or property damage.
Indicates special instructions on installation, operation or maintenance that
are important but not related to personal injury or property damage.
Electrical shock hazard — Disconnect power before installing or servicing.
Can cause severe personal injury, death or substantial property damage if
ignored.
To avoid severe personal injury, death or substantial property damage, never
connect the load terminals to a load that takes more current than the amount
listed for the relay in the electrical ratings.
Use copper wire only. Use of any other type of wire could cause a fire hazard
resulting in severe personal injury, death or substantial property damage.
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.
To the installer
Specifications
Weil-McLain
model
number
Transformer
voltage Switching
action Thermostat
current
amps
Single-phase motor
rating
120 VAC 240 VAC
WMR-21 120 V 60 HZ
15 VA DPST .18 10 A,
¹⁄₃ HP 10 A,
¹⁄₂ HP
WMR-22 120 V 60 HZ
15 VA DPDT .18 10 A,
¹⁄₃ HP 10 A,
¹⁄₂ HP
Part description Weil-McLain part number
Plug-in relay (24 VAC coil) 510-311-021
