Operating Guide

Water Heater Time Switches
The WH40 provides a convenient external override switch. Utilities in many areas of the country offer two
electric rates for residential or commercial customers. One rate has the regular daytime electrical rate, the other
is “off peak” rate. The off peak rate provides customers with “lower-priced” electricity during the nighttime
and weekend periods. These time switches allow the customer to shift electricity use into these off-peak time
periods in an attempt to save utility costs.
Applications
Water Heater Control for:
• Residential • Commercial • Industrial • Institutional / Schools • Military Facilities
Specifications
Case – Drawn steel 7-3/4" (19.7 cm) High, 5" (12.7 cm) Wide, 3" (7.6 cm) Deep in gray finish. Spring hasp, with hole
for lock, holds permanently attached, side hinged door closed. Three mounting holes on back plus handy box mounting
holes.
Knockouts – Combination 1/2"-3/4" nominal knockouts, one on back and each side of case and two on bottom.
Special Voltages and Cycles – See Time Switch Motors for available motors.
Switch Rating – 40 Amp Resistive, Inductive or Tungsten 120-277 VAC; 1000 VA pilot duty 120-277 VAC; 2 HP
(24 FLA) 125 VAC; 5 HP (28 FLA) 240 VAC.
Model # Switch Clock Supply Volts 60 Hz Watts External Switch Amps/Pole
T104-20 DPST 208-240 10000 No 40
WH40 DPST 250 10000 Yes 40
For additional trippers (1 ON / 1 OFF per pack), order No. 156T1978A.
Time Switches
WEATHERPROOF • ENERGY CONTROLS • PROFESSIONAL LIGHTING • POOL & SPA • SURGE PROTECTION • CONSUMER
35
The
"LITTLE
GRAY BOX" ®
2.75 lbs
1.25 kg
C22.2-177
LR3730
UL917
-40°F
(-40°C)
to
130°F
(54°C)