INTERMATIC WH21 Electric Water Heater Time Switch Instruction Manual

INTERMATIC WH21 Electric Water Heater Time Switch

Specifications

• Model: WH21
• Type: Electric Water Heater Time Switch
• Power Supply: 250V
• Trippers: ON Tripper (Silver), OFF Tripper (Brass)
• Terminal Block: LINE 1, LINE 2, GRD
• Indicator Lamp: Indicates power status
• Manual Control: Allows manual operation of the switch
• Grounding Screw: For proper grounding

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

1. Step 1
   Checking

   • Make sure the Time Switch and the water heater VOLTAGES are the same.
   • Make sure the water heater rating in WATTS is not over the maximum capacity of this Time Switch.
   • Make sure the water heater is wired with COPPER wire.
   • Do not connect ALUMINUM wires to the terminals of this Time Switch. Consult an electrician if the existing wires are ALUMINUM.
   • Disconnect power at the circuit breaker(s) or disconnect switch(es) before installing or servicing.
   • B. Planning and Measuring:
   • Here is how the water heater is wired now, BEFORE the installation of this Time Switch:
     

2. Service Box – The water heater should have its own (separate) fuse or circuit breaker in the electrical panel.

3. Junction Box – The wiring may or may not include this convenience box. It may contain a disconnect switch and/or receptacle if a water heater is connected.

4. Water Heater Connection – This is a rigid or flexible (metallic or plastic) cable containing 2, 3 or 4 insulated wires of different colors.

5. Water Heater Terminal Box – This is part of the water heater where the power supply wires are connected.

Here is the modified wiring, AFTER the Time Switch is installed

• Plan a convenient location for the Time Switch, preferably eye level (also out of reach of small children), and such that existing cable
  (Fig. 2, or Fig. 3 Item #3) may be utilized.

• Measure the distance (Item #5) from the Time Switch to Water Heater Terminal Box (Item #4). Also measure the distance (Item #3) from Time Switch to Junction Box if existing cable (Fig. 2, Item #3) is too short. Allow for slack and 6 inches of hook-up leads at each end to facilitate wiring connections.

Materials Needed
If the water heater is HARD WIRED: (See Figure 2)

• Obtain a piece of cable, the SAME TYPE (that is, metallic or plastic) and SAME GAUGE with COP PER conductors to make Item #5 connection (and Item #3, if needed) as shown. See also gauge selection chart below.
• Obtain 2 cable connectors (Item #6) to fit the cable above.

If the water heater is CORD and PLUG connected: (See Figure 3)

• Obtain the SAME TYPE and GAUGE cord set with plug as presently used on (Item #3) and 2 strain relief grommets (Item #7) to fit THIS cord set.

Tools Needed
Hammer, 1/4″ wide screwdriver, drill, pliers, wire cutter and stripper.

Size of Fuse or Circuit Breaker| Minimum Gauge of Copper Wire| 125 or 250 VAC| Water Heater Capacity
---|---|---|---
125 VAC| 250 VAC
A| #AWG| A| W| W
15| 14| 15| 1875| 3750
20| 12| 20| 2500| 5000
25| 10| 25| 3125| 6250

Step 2
Disconnect power at the circuit breaker(s) or disconnect switch(es) before installing or servicing. Pull plug, if cord is connected; remove fuse or open circuit breaker if hard-wired. More than one circuit breaker or disconnect switch may be required to de-energize the equipment before servicing.

Step 3
Mount timer case on wall as outlined in step 1B. Mark top mounting hole. Drill hole in mounting surface and drive screw into hole. Hang timer on screw. From the inside put screws into two bottom mounting holes. Use anchors if necessary.

Step 4

If the water heater is HARD WIRED

• Remove the cover of water heater terminal box (Fig. 1, Item #4). IS ELECTRICITY TURNED OFF? NOTE COLORS OF WIRES. Disconnect wires and cable connector. Remove the most convenient knockout of the time switch case and attach cable (Fig. 2, Item #3) and cable connector to case. If a 3/4 inch knockout is needed, remove the 1/2 inch knockout first, then the 3/4 knockout. Pre-pare another cable (Fig. 2, Item #5) by stripping the ends of wires 1/2 inch. Using cable connector (Fig. 2, Item #6), attach this cable to water heater terminal box and then the wires to water heater terminals.
• NOTE: If there were green and/or white wires in the terminal box before, connect the same colors to these same terminals. TIGHTEN TERMINAL SCREWS FIRMLY (torque 20-30 Lb In.). Remove another knockout of the time switch case and connect the other end of this cable to the case, using the other cable connector, Item #6.

If the water heater is CORD and PLUG connected
Remove plug at end of water heater cord (Fig. 1. Item #3). Split cord about six inches and strip wire ends 1/2 inch. Remove the most convenient knockout of the time switch case and attach cable (Fig. 2, Item #3) and cable connector to case. If a 3/4 inch knockout is needed, remove the 1/2 inch knockout first, then the 3/4 knockout. Install strain relief grommet (Fig.3, Item #7) and attach cord to case as shown. Next, install strain relief grommet to the other cord set (Fig. 3, Item #5) and attach cord set to case as shown below.

Step 5
Move insulator out of the way and connect the wires coming from the service box and from the water heater to the terminals of the time switch mechanism. For wiring connections regarding a specific model, refer to diagram inside the time switch door. Attach wire ends to time switch terminals as shown in wiring diagram. Insert only the stripped copper ends of wires UNDER the pressure plates of terminal screws as shown. Using 3/16″ or larger screwdriver, TIGHTEN TERMINAL SCREWS FIRMLY (torque 20-30 Lb In.).
Note: Time Switch may not operate if terminal screws are loose. Now replace front insulator cover. See the illustration below.

Step 6
Using pliers, grip folded down hasp on side of case and rotate it upward as shown. Also, install external 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.

Step 7
Set the daily program – see operating instructions 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 length 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.

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 revolutions 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.

To purchase extra trippers: order part no. 156EB1945A for a set of two (2) ON and two (2) OFF trippers.

http://waterheatertimer.org/Intermatic-timers-and-manuals.html#WH21

References

• Intermatic timers and manuals

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