48.8 Hp 480 Motor

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Fordean

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
Jraef said:
Wow, that's hard to read, but it looks like it is 69.5A FLA? That's a far cry from 48A!

That makes me wonder if they have some sort of VFD integrated into the unit and they are using that to limit the output to 48A, then using that value on their chassis label... very strange way of doing things.
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The duty cycle is S3-60%
i will post better pic Its hard ftom cell phone
 
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Fordean

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
Inside controler Vfd sounds correct
 

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augie47

augie47

Moderator
Staff member
Location
Tennessee
Occupation
State Electrical Inspector (Retired)
TYhe spec on the washer shows power at 41kw.. and your fuse protection at 63 amps.. That does not match your motor data sheet. I'm sure jrafe understand the reasoning.
 
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Fordean

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
augie47 said:
TYhe spec on the washer shows power at 41kw.. and your fuse protection at 63 amps.. That does not match your motor data sheet. I'm sure jrafe understand the reasoning.
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I have conductors 208volt side 1/0awg and
#4 180 feet to exterior remote on 480side

Fusing 150 amps @ 208 volts
And 70 on 480 volts i can install 100 amp thermo magnetic in stock Square d after i ordered now telling me 3 months lead time
What would u suggest line side 208 breaker And load side 480 using thermo magnetic breakers
 
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F

Fordean

Senior Member
Location
New Jersey
Occupation
Electrical Contractor
kwired said:
That is how it works with most motors with normal torque characteristics.

If you have one that is not listed in the tables you about have to go with nameplate amps or any manufacturer instructions if there is any that address this.

Fordean, remember you need 125% for conductor so at least a 60 amp conductor.

thermal-magnetic breaker can be up to 250% though often times it can be somewhat less. My square D motor slide calculator says a 100 amp breaker for a 50 HP motor is what they suggest, NEC would allow up to 175 for the 50 HP motor. 250% on 48 amps (with next size higher allowance) should let you go to 125 amps with this 48 amp motor.
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I have access to 100 amp 480 breaker U think it will hold inrush ? All breakers are 12 week backordered
 
T

topgone

Senior Member
Jraef said:
LOL... 60% of 37kW = 22.2kW. Bingo...
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When we consider the duty cycle of an equipment, it doesn't mean that the duty cycle multiplied by the rating of the equipment will be the "equivalent" power drawn by the equipment for one whole cycle! Since duty cycle has something to do with "On" and "Off" (usage), the correct formula wrt to usage will be the square root of the duty cycle times the equipment draw when ran. In this case, 37 kW X sqrt(0.6) = 28.66 kW.
 
kwired

kwired

Electron manager
Location
NE Nebraska
augie47 said:
TYhe spec on the washer shows power at 41kw.. and your fuse protection at 63 amps.. That does not match your motor data sheet. I'm sure jrafe understand the reasoning.
Click to expand...
With soft starter you can go with lower overcurrent device setting than you can with across line starting.
 
B

Bwas

Member
Location
Florida
Fordean said:
This is a cord and plug 8800 psi power washer Used to remove concrete from shoring steel From germany (Karcher )
Its remote exterior I have no motor starter in design Dont believe one is on unit
Unit operates when trigger is pulled on nozzle Little puzzled on this motor operation manual is useless
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Sounds like a 40 KW rated motor maybe? Make sure you are using full load amps and not some running current. The Germans love to give you brake horsepower for the load driven and the corresponding running current because they don't NEC, then ship you an NEC compliant motor nameplate that does not match the info they gave you previously. All of the sudden your entire service is undersized. I see it all the time on submerisble pumps.

Sounds like you have the motor in hand though so you should be good.
 
E

Eddie702

Licensed Electrician
Location
Western Massachusetts
Occupation
Electrician
From what I have seen in the HVAC field and have run into this many times that OEM motor amps and horsepower don't always match standard motors.

We had a cooling tower replacement and it was an exact replacement. The customer has forgot to anti freeze the tower and whoops it froze up.

The old tower had 30 hp motors 480 volt. The new tower came in with "30 hp" motors 480 volt but the amps was like 30% more. (I don't remember all the #s)

Obviously this would require a completer rewire to use these. pipe, conductors starters and breakers.

I called Reliance in TN. and bitched. They told me "they are oem motors we can mark them any way we want" They were 50 hp motors with 30 hp name plates and they told me that was perfectly fine to do.

They changed there tune when they found out they were not getting paid for the tower. They sent a guy up from TN and he swapped out the motors for standard 30 hp motors

But that doesn't change the OEM thing. It goes on all the time and I have never gotten an explanation on it.

You look on a lot of packaged AC unit motors and you will find horsepowers and amps that don't line up with "CODE" stuff.

I was always told if you replace an OEM motor in a packaged unit go by amps and forget the HP marking. And it works

They get away with this because on packaged units we wire to MOCP & MCA

These water towers had sep 3 phase feeds for the blower motor (the ones I questioned) and separate feeds for the pumps and basin heaters
 
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