I have used Russelectric switchgear for most of the hospital projects that I have done. It has been my perception that they are the premier manufacturer of reliable paralleling switchgear. However, for an upcoming State of Ohio project, I need to specify three manufacturers. Has anyone had...
NFPA 99 mentions natural gas as an approved fuel source, if it can be considered to be reliable. However, many states do not consider it reliable, and require an on-site fuel.
I am designing an emergency system for an Ohio hospital, including new generators. In other states that I have worked, the amount of on-site fuel capacity (hours of run time at full load) is clearly spelled out by the State. In Ohio, though, I can not find any requirement. Could someone familiar...
I design a lot of installations with multiple emergency generators connected in parallel (typically 480 volt diesel engine units). For many years, Caterpillar has always promote an "optimum pitch" generator, which is usually around 4/5 pitch. Other manufacturers have claimed that in order to...
I have two conduits to an outdoor switchgear. One conduit will contain 24 VDC power and control wiring. The other will contain 120 VAC power wiring. Also, in the switchgear there is a set of 100:5 Current transformers. I need to bring the leads from those ct's back in one of the two conduits...
Fusing is already in place. A 2-pole knife switch on the locomotive disconnects the batteries from the locomotive and connects them to a plug on the side of the loco for connection of a charger. At the knife switch, there is a 10A fuse in each leg. Buying a charger is out of the question for...
I am trying to construct a simple 72 VDC power supply to charge the batteries on a diesel electric locomotive. I need about 5 amps. I used a standard wallbox lighting dimmer, connect to a bridge rectifier to go from 120VAC to variable DC. I thought I should have some filtering on the output...
When Alco first got into the Diesel locomotive business in the 1940's, they partnered with GE. GE provided all of the electrical components. The generator is belt driven off the engine. It is actually two generators in one housing. One end of the unit is the exciter generator, which provides...
I'm not sure if this is the right forum for this question or if I should go to Electric Power Engineering. I am working with a group that is restoring a 1950's vintage Diesel Electric Locomotive. The Auxiliary generator (used for battery charging and controls) does not work. It is a 25 kW, 75...
The elevators in a 50 year old building were recnetly upgraded by Otis elevator to new 6-pulse scr drive units. The building is 18 stories. Whenever a new elevator is running, a singing or humming sound can be heard. We traced the source to the elevator feeder conduit that runs from the...
Several years ago I had this same problem with a large chiller motor. An oscilloscope trace showed that even though we were using a closed transition starter, there was a large spike during the transition. In this case, setting the instantaneous trip up a little took care of the problem. Since...