flexible cords on HRV

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electrofelon

electrofelon

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Location
Cherry Valley NY, Seattle, WA
I am working in a commercial setting that has a grid/dropped ceiling. There are two lifebreath heat recovery ventilators installed above the drop ceiling. The HRV units have factory installed 120v cord and plug. Any thoughts on how to power these units in a code compliant manner considering 400.7 and the implications of not following the manufacturers instructions and modifying the unit by cutting the cord out and hardwiring it with say mc?
 
electrofelon said:
I am working in a commercial setting that has a grid/dropped ceiling. There are two lifebreath heat recovery ventilators installed above the drop ceiling. The HRV units have factory installed 120v cord and plug. Any thoughts on how to power these units in a code compliant manner considering 400.7 and the implications of not following the manufacturers instructions and modifying the unit by cutting the cord out and hardwiring it with say mc?
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Are you concerned about having the manufacturer's cord material in an environmental air handling space above the ceiling or with having to put a receptacle above the ceiling to connect the cord to? Or both?
 
raider1 said:
I agree, IMHO 400.8 (5) would prohibit the appliance from being installed above a suspended ceiling.

Chris
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One suggestion which has been made in the past would be to frame a "cord well" from the level of the suspended ceiling up to the appliance to allow the cord to plug into a receptacle facing into that well without ever being above the ceiling.
 
raider1 said:
I agree, IMHO 400.8 (5) would prohibit the appliance from being installed above a suspended ceiling.

Chris
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I think the cord is part of a UL listed piece of equipment, and the NEC does not really apply to the components of a UL listed piece of equipment.

If you can put the equipment up there, a piece of the equipment can go with it.

That does not mean that a rabid cord hating inspector might not incorrectly red tag you for it.
 
petersonra said:
I think the cord is part of a UL listed piece of equipment, and the NEC does not really apply to the components of a UL listed piece of equipment.

If you can put the equipment up there, a piece of the equipment can go with it.

That does not mean that a rabid cord hating inspector might not incorrectly red tag you for it.
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Thats what I have always been unsure of. It seems many say that it is a flexible cord and subject to article 400 but Im not convinced that applies to factory ul listed equipment. If the former was true, think of how often a cord would violate the "shall not be used as a permanent wiring method" clause.
 
Some of the issues that may arise ---- Is the ceilng part of a firerated assemby? & Nec will address the previously mentioned plenum issue.
 
electrofelon said:
The HRV units have factory installed 120v cord and plug. Any thoughts on how to power these units in a code compliant manner considering 400.7 and the implications of not following the manufacturers instructions and modifying the unit by cutting the cord out and hardwiring it with say mc?
Click to expand...

I believe the factory supplied cord is considered a power supply cord and UL listed differently than flexible cords and is not subject to the limitations of Article 400. May want to check out these two threads which are applicable to your situation:

http://forums.mikeholt.com/showthread.php?t=154737

http://forums.mikeholt.com/showthread.php?t=152931&highlight=flexible+cord+above+ceiling
 
jtinge said:
I believe the factory supplied cord is considered a power supply cord and UL listed differently than flexible cords and is not subject to the limitations of Article 400. May want to check out these two threads which are applicable to your situation:

http://forums.mikeholt.com/showthread.php?t=154737

http://forums.mikeholt.com/showthread.php?t=152931&highlight=flexible+cord+above+ceiling
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I agree wholeheartedly. Your second link is to a thread initiated by Mike Holt himself and opened by Ryan Jackson.

Manufacturer assembled and listed power supply cords and cord sets are not listed as flexible cord and are therefore not within the scope of Article 400 as they are not terms included within the scope.
 
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