Hot water heater

[Dennis Alwon]

Also they have a lower ampacity for 240V then the 208V. With resistance elements the higher the voltage the larger the draw so that chart is wacky wrong...

 

[kwired]

Does that say max overcurrent protective device? I am not sure that would limit the device to 25 amps.

Good question, if you look at 4500 watt three phase right below the highlighted single phase, it still says 25 amp overcurrent and 10 AWG conductor - yet a 4500 watt 240 volt three phase unit should draw about 10.8 amps.

Also they have a lower ampacity for 240V then the 208V. With resistance elements the higher the voltage the larger the draw so that chart is wacky wrong...

If it is rated 4500 watts at 208 volts it will draw more current then same wattage at 240 volts. Most common applications you see with 208 volts use 240 volt rated elements though so the total wattage will be reduced because of lower voltage applied.

 

[GoldDigger]

And some heaters have a jumper link on the terminal area of the heating element to select a target voltage of either 208V or 240V.
For such a unit a lower load current at 240V would be perfectly reasonable.

 

[electroman00]

50 gal.http://www.rheem.com/product/residential-electric-water-heaters-performance-series-standard-electric
Geo

Not that it says exactly which model...

Heaters furnished with standard 240 volt AC, single phase non-simultaneous wiring, and 4500 watt upper and lower heating elements.



There are NO Relays, the top element has a double throw thermal switch and the bottom is a single throw Thermal Switch (TS).
Top TS feeds the bottom TS after the top is satisfied.

That says which element is the hard worker. Bottom.
When a heater can not sustain in cold weather, the bottom is bad.



4500w heaters you use 10/2 and sleeve with metallic flex from the wall to flex 90 connector on the heater.
The most important connection is the grounding wire, especially where metallic plumbing pipe is use.

Although it is fairly impossible for both elements to turn on at the same time, most of the time one of the TS contacts cease/weld fail.
That's usually a good indication the element is bad.

Top of the tank has Pressure Relief Valve which should be tested / cleared regularly to ensure the tank doesn't blow up if something fails.
About 5% of the one's I've tested are frozen.

 

[jap]

Not that it says exactly which model...

Heaters furnished with standard 240 volt AC, single phase non-simultaneous wiring, and 4500 watt upper and lower heating elements.

View attachment 13916

There are NO Relays, the top element has a double throw thermal switch and the bottom is a single throw Thermal Switch (TS).
Top TS feeds the bottom TS after the top is satisfied.

That says which element is the hard worker. Bottom.
When a heater can not sustain in cold weather, the bottom is bad.

View attachment 13917

4500w heaters you use 10/2 and sleeve with metallic flex from the wall to flex 90 connector on the heater.
The most important connection is the grounding wire, especially where metallic plumbing pipe is use.

Although it is fairly impossible for both elements to turn on at the same time, most of the time one of the TS contacts cease/weld fail.
That's usually a good indication the element is bad.

Top of the tank has Pressure Relief Valve which should be tested / cleared regularly to ensure the tank doesn't blow up if something fails.
About 5% of the one's I've tested are frozen.

From and advise standpoint,,,,Just to clarify, this statement may be speaking for everyone else,,,,, but not me personally.

Jap>