fire pumps,raceway condensation

[jimalone]

Gentlemen,
i have two questions.
where a raceway is in a condenation area what is the aproved remedy?

can a 480 motor run ok and eff. on 406v..i am referring to the 15% drop on fire pumps? (or am i reading it wrong?)

thank you

 

[rick hart]

Re: fire pumps,raceway condensation

One remedy is to seal the conduit openings to air from getting in the conduit right outside the condensing areas. Be sure that whatever sealant you use does not damage the insulation on the wires. Fiberglass works well and can be removed in the future.

Not sure about that "EFF". Do you mean efficiently or effectively?
The motor will work, for how long is anyone guess but it will be effective while it does.
Efficiency will drop considerably and the motor will pull more current than at 480V. Overloads are not an option on a fire pump.

 

[tom baker]

Re: fire pumps,raceway condensation

Your motor is not rated 480 its rated 460 volt to use on a 480 system. Take a look at the nameplate.

 

[don_resqcapt19]

Re: fire pumps,raceway condensation

Jim,
The 15% voltage drop rule for fire pumps applies to the starting current, not the running current.

695.7 Voltage Drop.
The voltage at the controller line terminals shall not drop more than 15 percent below normal (controller-rated voltage) under motor starting conditions. The voltage at the motor terminals shall not drop more than 5 percent below the voltage rating of the motor when the motor is operating at 115 percent of the full-load current rating of the motor.