Recent content by electromike

I just had to replace a tie section of a main tie main. This was sporty. This all came about because of "master electricians."

It is 460v/60hz

x/10 ct's! Never seen this but it would explain this difference.

I have encountered a situation with GE motor starters where the OL selection chart for a size 5 starter with CTs and a 168 Fla at 150 hp calls for almost a double size heater element than what would be expected with a 5 amp secondary current on the CT. The heaters recommended by the chart would...

I was able to locate Wescode C385P SCRs from a supplier. We now have the inverter running but this is only until this inverter gets retrofitted with IGBTs by the OEM or we buy a new one. Hopefully certain people will learn that paint that is still glossy in not the only metric for figuring...

Gunnar, the aplication is for a UPS inverter. The link you provided was very helpful. Thanks.

jraef, I got the "invertere grade" from a Powerex rep. when I give him the device numbers. My experience is with DC motor drives and I know what a phase control thyrister is but the inverter grade stuff was new to me too.

I would like to know what electrical parameters make the difference between a inverter grade thyrister and a phase control thyrister? I am tring to cross refrence an old obsolete inverter grade thyrister in an attemp to make a quick repair to a UPS system at my facility that has a shorted scr in...

I need to know which codes,API or ANSI ect., cover the installation of compresion and threaded steel tubing used in high pressure hydrogen gas service. This information is needed after an incident where a maintenance technican changed several 3/8" tubing valves in a valve/regulator tree fed by...

Thanks for the info electripete! I am tring to "up" the skills of our technicians by introducing them to the concept of the phase-to-phase short ( I'm tired of the "Megger Test" being the final and only word on motor falures in my plant which thus causes un-needed drive change-outs ) and I...

I should have stated the "Phase-to-Phase" DC resistance. Oops!

Does anyone know what an acceptable "Standard" percent difference of DC resistance one should find in LV 3 phase motor stators?

waross, you are right about the troubleshooting being challenging. It was a troubleshooting situation that an electrical contractor was working on, with dificulty, that brought the fact that there are 120ac control ciricuits that are switched on the neutral to my attention. To my supprise our...

In the United States. The two facilites are Japanese owned and we have had some isues with differing approaches as far a technical issues go(Code be damned). We do use some positive-common DC and I think this is where some inexperienced person who didnt understand the difference with AC and DC...

Does anyone have experience with switching the neutral instead of the "Hot" conductor in control circuits except in motor starter buckets. I have encountered this practice on a DCS system in a chemical manufacturing facility.I am told this is a safer practice in that all conductors in the field...