Dynamic Brake Resistor - Exposed Live Parts

[123MB]

Hi All

First of all sorry for the silly question, I lack a bit of experience in this area

Background:

We are designing an outdoor enclosure for a dynamic brake resistor where a bit of water may enter the enclosure from time to time. I am trying to determine the practicability of insulating the live parts inside this section in order to reduce the possibility of the water causing short circuits and tripping the drive.

Detail question:
1) On a typical wirewound dynamic brake resistor, is the resistor wire typically a live exposed part? Or is it somehow insulated, i.e similar to a heating coil in a space heater?

2) If the resistor wire is a live exposed part, is an enamel coated brake resistor the only way to achieve an equivalent level of insulation?

3) If one had an enamel coated resistor, would it be practicable to require that connection lugs used for cable connection onto the resistor shall be protected with insulating heat shrink, thereby resulting in the entire resistor installation being insulated?

Thanks

 

[EdStainless]

DBR in loco use are metal plates held by segmented ceramic insulators. A metal frame holds it all together and a bit of water splashing on them is a non-event.

http://www.mosebachresistors.com/resistors_rl.html

You need fans for this amount of power dissipation.

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P.E. Metallurgy, Plymouth Tube