Recent content by cvirgil

What is the difference between the two?

I'm using 12v, PAR36 as emergency lights. Instaed of using the typcial bugged eyed unit i will have thefixtures mounted remote and fed through an inverter system which operates at 120v. I will be installing a transformer to step down from 120v to 12v. Can the PAR 36 operate on AC voltage?

In looking at this more closely it looks like there are three levels for Margin of Protection. Does anyone know how to find vaules for: 1. Chopped Wave Withstand value 2. Front of Wave Value. 3. Equivalent switching protection level value. Also, is it typcial to use normal duty arrestier foir...

How does one typically size the surge arrestor and surge capacitors for a system? I;m intretse din fidng out what kV surge arrestor is need with a particulat BIL. Is protcetion of the BIL level affected by a higher surge arrrestor rating and grounding scheme?

Thanks. The tranformer has a lower BIL rating than the switchgear. Would that make a difference?

If the transformer is close coupled to the medium voltage gear, would this setup be a canidate to install surge capacitors since the length of cable would be small to the primary side?

The details are: Voltage: 13.2kV, grounded Type of transformer: VPI dry type, 2000kVA, indoor The transformer is fed from a 13.2kV VCB in a sub distribution switchgear line up. This is not the incoming utility service. The incoming utility service is approximatley 1000' feet away which...

An underground duct bank consist of concrete encased PVC conduits. Is there any concern regarding lighting strikes entering the building into the electrcial equipment through the ductbank?

Is it typical to also install surge capacitors in addition to the surge arresters. It's my understanding that the arresters are ineffective at controlling a surge's rate of rise. Could the sure arresters be installed in the breaker cubicle instead of at the transformer.

1. Do the BIL levels for switchgear and transformers need to be coordinated. For example, if a switchgear is rated for 90kv BIL and the transformer is rated for 30kv BIL is the transfomer under rated? 2.Is it typical to provide surge protection on transfomers that are served on the primary from...

I'm reviewing results from a megger test on 600V condcutors from Phase to ground and Phase to Phase. A-G = 700Megohm B-G = 1000Megohm C-G = 800Megohm A-B = 1600Megohm B-C = 1580Megohm A-C = 1400Megohm Any idea as to why the values are different? All phase condcutors are the same length.

Anyone know the typical life expectancy of fiber optic cable installed undergroiund in conduit? What are the factors affecting life expectancy?

Anyone know the typical life expectancy of fiber optic cable installed underground in conduit? What are the factors affecting the life expectancy? Thanks.

Anyone know the differenc bewteen these two types of windings for low voltage generators?

Good information listed here but I guess I should have been more specifcic. Anyone know of good literature on the baiscs of generator paralleling and load sharing?