Space Heater Wattage Required

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Motor:
HP: 450
Voltage: 2300
Phase : 3
Load speed 1180
size:588

Heater:
120V single phase (external source)
435W

By size:588, are you indicating that the Frame is a 588/9T? Which indicates that it is a horizontal motor. Can you provide the manufactirers name from the dataplate?
 
electric_cal said:
Motor:
HP: 450
Voltage: 2300
Phase : 3
Load speed 1180
size:588

Heater:
120V single phase (external source)
435W

By size:588, are you indicating that the Frame is a 588/9T? Which indicates that it is a horizontal motor. Can you provide the manufactirers name from the dataplate?
Click to expand...

Siemens and motor is vertical.
 
Heater:
120V single phase (external source)
435W

I would think that based upon the above dataplate information on the space heater installed by the manufacturer, and your previous current reading of 0.6 amps, that the space heater has degraded. It appears to only be producing 72 watts of heat. This could be verified by taking a resistance reading to see what resistance value the space heater has. If the manufacturer determined that 435 watts at 120 volts is the correct space heat required, based upon the motors design and application, then I would consider it to be correct.
 
electric_cal said:
Heater:
120V single phase (external source)
435W

I would think that based upon the above dataplate information on the space heater installed by the manufacturer, and your previous current reading of 0.6 amps, that the space heater has degraded. It appears to only be producing 72 watts of heat. This could be verified by taking a resistance reading to see what resistance value the space heater has. If the manufacturer determined that 435 watts at 120 volts is the correct space heat required, based upon the motors design and application, then I would consider it to be correct.
Click to expand...

Thank you. I called the manufacture and its one heater in there, so one resistance value.

If I measure resistance while the heater is off, according to ohms law I should be reading about 33 ohms. Anything higher will confirm that the heater has degraded.

I may need to take this heater out of service to get a good resistance reading due to motor being on causing more heat.
 
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goodoboy said:
I may need to take this heater out of service to get a good resistance reading due to motor being on causing more heat.
Click to expand...
The extra heat from the motor will only affect the heater resistance in a meaningful amount if it is specifically designed to be "self-regulating" like a heat tape.
Normal resistance wire will not change its resistance much over the temperature range you are looking at.
Now if you want to measure motor temperature with the heater on and off, yes you will have to shut it down.
 
GoldDigger said:
The extra heat from the motor will only affect the heater resistance in a meaningful amount if it is specifically designed to be "self-regulating" like a heat tape.
Normal resistance wire will not change its resistance much over the temperature range you are looking at.
Now if you want to measure motor temperature with the heater on and off, yes you will have to shut it down.
Click to expand...

That is what I was trying to get at in post 17. If it would be any kind of self regulating heating such as many heat tapes are, the resistance will vary depending on temperature, and this of course will result in varying current depending on the need at the time of the reading.

Like I said I don't know what kind of heater is commonly used for the application, but sure sounds like it may be a good design practice to use something self regulating for reasons mentioned back in post 17.

Other thing for OP to consider is just how condensing of an environment his application is in. Replacement of such heater may not be worth it if there is little condensing going to happen. I gather he is likely in Huston area, now if the motor is outdoors there may be some concern, but other locations probably not so much of a concern, as you likely just don't have enough temperature change to cause condensation, but you definitely do have the humidity.
 
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