Hot water heater

[geochurchi]

Hi All, new water heater 240 VAC, 2 elements each 4500 watts,mfg specs a 50 amp breaker # 8 conductors,some people say 10/2 and a 30 amp breaker ad both eleminates will not be on at the same time, my thought is follow the mfg. specs

Thoughts
Geo

 

[jumper]

Well code says to follow mnfr. specs, but I am curious.

What is the make and model?

I have never seen a standard 4500W resi WH with those specs.

 

[winnie]

Follow the mfg specs, or contact the mfg if the specs seem wrong. Don't simply follow what is common for other seemingly similar hardware.

Commonly water heaters only operate 1 element at a time, and a 30A breaker is appropriate. However if this is a strange beast and can operate both at once then you would need the 50A breaker and depending on wire type you might need #6 conductors.

-Jon

 

[geochurchi]

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

 

[jumper]

None of the spec links on that site will open for me.:rant:

 

[Barbqranch]

I looked at the spec sheet, and for 4500 W it lists 25 A (at 240 V). Perhaps the OP doubled that, not realizing that only one element can operate at a time. For 9000 W they do list 50 A breaker.

 

[winnie]

The specification sheet on the page that you linked says:
"Heaters furnished with standard 240 volt AC, single phase non-simultaneous wiring, and 4500 watt upper and lower heating elements"

The installation manual says " The voltage requirements and wattage load for the water heater are specified on the rating plate on the front of the water heater. "

So without knowing exactly what it says on the rating plate we can no more than guess. A normal water heater with two 4500W elements would have a total wattage of 4500W because only one element is on at a time.

-Jon

 

[jap]

The specification sheet on the page that you linked says:
"Heaters furnished with standard 240 volt AC, single phase non-simultaneous wiring, and 4500 watt upper and lower heating elements"

The installation manual says " The voltage requirements and wattage load for the water heater are specified on the rating plate on the front of the water heater. "

So without knowing exactly what it says on the rating plate we can no more than guess. A normal water heater with two 4500W elements would have a total wattage of 4500W because only one element is on at a time.

-Jon

How would one know that only one element operated at a time?

JAP>

 

[jumper]

How would one know that only one element operated at a time?

JAP>

The WH usually has two stats, upper and lower, you can turn them up and down and verify current flow with ammeter.

 

[jap]

That's probably the norm but common sense would say both heating elements have the possibility to be fired at the same time and should be wired for such.

JAP>

 

[jap]

The WH usually has two stats, upper and lower, you can turn them up and down and verify current flow with ammeter.

That's funny right there......


jap>

 

[jap]

excuse me folks while I sleep over and adjust the thermostats on your water heater to make sure the 30 amp circuit I pulled to it dont trip......:lol:


JAP>

 

[jumper]

That's probably the norm but common sense would say both heating elements have the possibility to be fired at the same time and should be wired for such.

JAP>

When the upper t-stat is satisfied, power is then sent to lower stat. Probably relay in upper t-stat.

While the possibility of a malfunction is possible, I imagine the probability is extremely low.

 

[jumper]

That's funny right there......


jap>

excuse me folks while I sleep over and adjust the thermostats on your water heater to make sure the 30 amp circuit I pulled to it dont trip......:lol:


JAP>

I am not sure what is funny.:?

WHs are really basic, you just wire it, set the stats and go. There are millions of these types of WHs wired with #10 and a 30A breaker with no problems.

 

[jap]

I dont wire a lot of electric water heaters and that's probably the case.

I'm just saying most would not know that.

Is there a min circuit amps and Max overcurrent protection indicated on Electric Water Heaters?

If I saw 2 elements at 4500 watts without something to tell me what size circuit to pull, I'd lean hard towards a 50 amp circuit.

JAP>

 

[ActionDave]

I dont wire a lot of electric water heaters and that's probably the case.

I'm just saying most would not know that..........

I would say most do.

 

[Dennis Alwon]

It is possible that both elements are wired to come on together. IN NC the power companies will not allow that setup for dwellings as far as I know because of the demand it would put on their system.

If this unit calls for 50 amps then there must be only one T-stat for both units but that is not what we see. Generally it is as Jumper stated.

Easy enough to check out... Remove the cover on the top and lower areas of the water heater and see if there are 2 stats or 1. If there are 2 sp t- stats then they both can come on at the same time. If he top one is a spdt then they will not come on together

 

[jap]

Shouldnt take that much investigating to figure out what size circuit needs to be pulled to a water heater.


JAP>

 

[jap]

I would say most do.

Doubtful,

Most should know what configuration of a contact block is needed on the back of a 3 position HOA selector switch also, but I doubt most know that a combination contact goes to the center neutral position when you mount it to the back of the operator.

JAP>

 

[jumper]

Shouldnt take that much investigating to figure out what size circuit needs to be pulled to a water heater.


JAP>

The name plate will probably state total connected watts. I did a quick search on Google and it showed it. 2 elements, upper and lower, 4500W each at 240V, but a total connected load of 4500W.