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Cost to operate water heater Do-it-yourself

Water heater contactors

Each water heater requires a separate contactor

Fasco H230A
Siemens Furnas 45EG20AF
Fasco H230A contactor
2-Pole 40A resistive
110V coil

Model has cover over points

Seimens Energy Co
Furnas definite purpose controller 45EG20AG

2-Pole 40A resistive
110V coil

When turned on, coil burden or coil VA is 7.3 Watts <> when activated, inrush is 27 Watts.
 
Life expectancy <> 0.5 - 2.0 million operations
What is a contactor?

Each time a compressor <> well pump <> refrigerator <> washing machine <> clothes dryer <> Heat/AC <> computer turns on, a contactor handles the job. Contactors (also called controllers or relays) are designed for electric switching jobs. Every home has contactors working each day. read wiki

For a water heater timer, a specific contactor is shown.

 

Choose:   Siemens 45EG20AF Definite Purpose -or- Fasco H230B -or Cutler Hammer C25BNB230A  > these are interchangeable 2-pole 30A contactors rated 40A resistive with a 110 volt coil. Other models include: Fasco H240B and Cutler Hammer C25BNB240A and economy-priced Honeywell DP2030B1002. Also solid state contactors are available at much higher cost.


Cutler Hammer C25BUB230A
Cutler Hammer C25BUB230A
Honeywell DP2030B1002 contactor
Honeywell DP2030B1002:
economy priced
Siemens 45EG20AF Definite Purpose Wires connected to 45EG20AF using female terminals

45EG20AF in box
Here is the 45EG20AF contactor bolted into a 6x6x4 enclosure using #8-32 x 3/4" bolts

Put contactor at angle leaves room for wire

Contactor maintenance
Life expectancy <> 0.5 - 2.0 million operations

Contact points stick sometimes

Solution: use nail file or emery board or folded sandpaper to clean off points.

Handy trick
Add indicator light so you can see when water heater is on. If points stick, indicator light remains on.
Indicator light

<> buy Grainger item 1XWK8
<> buy Grainger item 1CV90

Indicator requires another fuseholder.

Instructions for connecting indicator here and on page 3 near bottom