6000 watts 3 phase on electric water heater

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GoldDigger

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i get 220 because i measure a voltage between phases and i get 219

You can measure all you want, but the resistance of the heating elements is fixed and therefore the rated power will be delivered at exactly one voltage.
You can then figure the current at that voltage and then, if you really need to know, you can calculate the current at whatever the normal voltage is.
But all NEC load and current calculations are based on the nominal 240 or 230.
If the element is dual rated for 240 and 208, it will give the current and power separately at 208. Even if it does not you can calculate and use the current at the nominal voltage of 208 if that is what is supplied.
 

michalspike

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I'm trying to figure it out.Because plumbers blaming us for burning heat elements for water heater. Not sure what happen but according to plumbers elements burn because to much power
 

iwire

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in NYC Voltage is 120/240V i never understand that how it can be 240 if we measure it at almost 220V



In NYC I am sure some areas are 208 and some are 240.

You need to know which voltage if you want accurate results.

If you want to 'wing it', use 240 as the voltage and if the building is actually 208 volts the current will be less.
 

iwire

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but if unit is rated for 208and 240. witch number i should use for calculate my OCP

You would use the nominal voltage the building is supplied with.

You cant always tell this by reading the voltage. You said you measured 219 volts. Depending on if you measured that at the main or at the end of a branch circuit that could be a 208 service running high or a 240 service running low.

Check this chart out

ANSIC841.jpg


So to give you a rock solid answer we need the labeling of the unit and the true service voltage of the building.
 

GoldDigger

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You would use the nominal voltage the building is supplied with.

You cant always tell this by reading the voltage. You said you measured 219 volts. Depending on if you measured that at the main or at the end of a branch circuit that could be a 208 service running high or a 240 service running low.

Check this chart out

ANSIC841.jpg


So to give you a rock solid answer we need the labeling of the unit and the true service voltage of the building.
But to calculate the actual power of the element you need the nameplate information.
The OP seems to feel that a 6000 watt element will deliver 6000 watts at any applied voltage
 

don_resqcapt19

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Illinois
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retired electrician
I'm trying to figure it out.Because plumbers blaming us for burning heat elements for water heater. Not sure what happen but according to plumbers elements burn because to much power
Heaters burn out because they were connected to a higher voltage than they were designed for or, they were no submersed in water when they were powered.

The amount of power that the heated draws is fixed by the heater design and the applied voltage.
 

GoldDigger

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Heaters burn out because they were connected to a higher voltage than they were designed for or, they were no submersed in water when they were powered.

The amount of power that the heated draws is fixed by the heater design and the applied voltage.

You mean it does not get hotter the larger the breaker you feed it from? :angel:
 
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