Intermatic WH21 Operating Instructions

Step 6
Using pliers, grip folded down hasp on side of case and rotate it
upward as shown. Also, install exter nal push button in the inside of
cover by inserting plastic button into the rectangular and round holes
as shown then pressing round tabs into round hole in cover. Close
cover to make sure the holes in cover line up. Adjust, if required.
External
Push Button
Hasp
Adjust if required.
To open the door,
push the hasp
gently to the left
while pulling on the
door of the unit.
Step 7
Set the daily program - see operating instruc tions on page 7. Each
individual household should determine a schedule to suit their own
needs. Adjustments should be made for family size, hot water needs,
appliances, etc. In areas where time -of-day rates are in effect, consult
the electric utility company to find when the lowest rates apply. Then
set the time switch to operate the water heater when the electric rates
are lowest and adjust the schedule accordingly.
In setting the schedule, consider the facts that the temperature and
quantity of hot water will decline during the OFF periods depending on
amount used and Iength of OFF time. A typical schedule could be ON
at 6 a.m., OFF at 8 a.m. for morning use, and ON again at 5 p.m. and
OFF again at 10 p.m.
ON Tripper
OFF Tripper
ON Tripper
(Silver)
Time Mark
OFF Tripper
OFF Tripper
ON Tripper
(Brass)
View of Dial at Midnight
Typical Program
Page 6
Step 8
Check wiring, time setting (a.m./p.m.) and program. If hard wired, also
close Water Heater Terminal Box. Restore electric service (the reverse
of Step 2).

Operating Instructions

This Time Switch will repeat a preset schedule daily except when the
EXTERNAL MANUAL PUSH BUTTON is used. This manual button
permits the user to turn the water heater ON and OFF ahead of the
schedule. The Time Switch will resume the preset program by the next
scheduled ON or OFF operation. The diagram on the right shows the
mechanism and wiring of this Time Switch. The TIME MARK is used to
line up the correct time of day on the TIME DIAL. The ON and OFF
TRIPPERS turn the water heater ON and OFF at the times indicated
by their respective position on the TIME DIAL.
To Set Program
1. Grasp time dial firmly. PULL and remove time dial completely from
timer.
2. Remove all ON trippers (silver) and OFF trippers (brass). Use
pencil or paper clip if necessary.
3. Insert OFF trippers (brass) in slots for desired OFF times, but NOT
CLOSER than 2 hours apart.
4. Insert ON trippers (silver) in slots for desired ON times, but NOT
CLOSER than 2 hours apart. ON and OFF trippers may be spaced
1/2 hour apart from each other.
5. Replace time dial. PUSH IN FIRMLY. If any trip pers are near the
time mark, rotate time dial to avoid interference with mechanism
inside.
6. Turn time dial CLOCKWISE one or more revolu tions until correct
time-of-day is opposite time mark.
TO STOP AUTOMATIC OPERATION: (But with out stopping timer)
PULL outward on time dial until it clicks.
TO RESUME AUTOMATIC OPERATION: PUSH inward on time dial.
AFTER POWER FAILURE: (or if water heater was disconnected at
main panel) time dial must be reset to correct time-of-day.
DISCONNECT POWER AT THE CIRCUIT BREAKER(S) OR
DISCONNECT SWITCH(ES) BEFORE INSTALLING OR SERVICING.
TURNING THIS SWITCH OFF WILL STILL LEAVE THE POSSIBILITY
FOR HAZARDOUS VOLTAGE AT THE WATER HEATER.
Page 7
INDICATOR
LAMP
ON TRIPPER
(SILVER)
TIME MARK
TIME DIAL
OFF TRIPPER
MANUAL
(BRASS)
CONTROL
TERMINAL
GROUNDING
BLOCK
SCREW
250V
{
LINE 1
FROM
LINE 2
FUSE
}
GRD
GRD
BOX TO
WATER
HEATER
To purchase extra trippers: order part no. 156EB1945A for a set of
two (2) ON and two (2) OFF trippers.
Page 8 158--01753
WH21 Electric Water Heater
Time Switch
WARNING
Risk of Fire or Electric Shock
• Disconnect power at the circuit breaker(s) or disconnect switch(es)
before installing or servicing.
• Installation and/or wiring must be in accordance with national and
local electrical code requirements.
• Use #14 - #10 AWG wires, rated at least 90° C - COPPER conductors
ONLY.
• Do not remove insulator.
• KEEP DOOR CLOSED AT ALL TIMES when not servicing.
• Turning this switch off will still leave the possibility for hazardous
voltage at the water heater.
• More than one circuit breaker or disconnect switch may be required
to de-energize the equipment before servicing.
NOTICE
• Rotate timer dial clockwise only.
• Do not move the clock hands on the timer. Moving the clock hands
can damage the timer.
» Easy to Install
» External Manual Override
Switch
» Match Water Heater Off
Times to Peak Energy
Periods of Utility to
Reduce Demand
» External Load Indicator
» 25 A (6250 W) Resistive,
208-250 VAC, 60 HZ
» 1500 W Tungsten,
208-250 VAC, 60 HZ
» 2 HP, 20 FLA, 80 LRA @
208-250 VAC, 60 HZ