ballast tranfer devices

[Jason Electro]

I have a project coming up that has these ballast transfer devices. Basically from what i can make out on the diagram is these devices take a local lighting circuit, and an EM lighting circuit (feed from a generator backed up panel) and allow you to have a room with 10 lights in it, 8 off the local circuit and 2 off the EM panel ,and these are controlled by one switch.
has anyone worked with these before? am I on track as to what these do?

 

[dkidd]

I have used the ones by Bodine before. Your description is pretty accurate.

See

http://www.bodine.com/downloads/install/GTD.inst.(std).70100008.pdf

 

[don_resqcapt19]

A new rule for the 2011 code addresses the use of this device. 700.24

 

[dkidd]

See NFPA 2011 ROP 13-188 Log #3232 NEC-P13

Which says in part:


Load Control Relays are not suitable for transfer between two nonsynchronous
power sources because:
A. They do not have mechanisms required by UL1008 to prevent inadvertent
connection of the normal and emergency sources, and
B. They do not undergo fault-current evaluation that is required of UL1008
transfer switches.
Because it is so easy for engineers and installers to misapply Load Control
Relays as transfer devices on branch circuits, Article 700 should clarify the
correct application of these two devices. Efforts by UL alone have been
unsuccessful in preventing field misapplication of Load Control Relays as
transfer switches.

The Bodine device is UL1008 listed and 700.24 does not apply.

 

[Jason Electro]

thanks for the info

 

[dkidd]

I found a very good article explaning the use of 700.24 load control relays versus transfer devices:

http://www.etcconnect.com/img/whitepapers/Understanding-Emergency-Lighting-2010-update.pdf