Recent content by sefs

Adding a center tap is only going to work for between two legs of the delta. All of your wall connectors would have to be across the same two phases. If you do this more that once (across two other phases) you’ll instantly cause a fault between those two transformers.

It can be a code compliant service configuration, but it has fallen into obscurity. Here is an article describing some disadvantages Disadvantages And Regulations: Code Rules for Ungrounded Systems

Yeah, you’re either looking at getting your utility to convert your service to a center tap delta, or getting a 60 KVA isolation transformer. You could look into something more exotic like a delta/wye grounding transformer where the wye is connected to your delta feed and the delta isn’t...

Is this in an existing facility? Was there some sort of industrial process going on there before? Ungrounded delta setups are not very common even in commercial. Typically they were installed when you didn’t want the factory to stop for anything, and the idea is that you would be fine unless two...

Do you have a corner grounded delta feed? If so, have you tried the 277v mode through the dip switches? That mode changes the 120V to ground check to a single check of phase to neutral in the 277v wye configuration, which would be electrically identical to your corner grounded delta (obviously...

It wouldn't harm the generator at all (that's the purpose of load shedding), but what you are going with works just as well.

I wouldn't decrease setting on the HPWC; the generator is overload protected by it's load shedding capability with the 100A contactor. But it's up to you, best of luck.

I have it setup to be load shed from the transfer switch. I have my AC, EVSE's, garage heater, and hot tub on contactors controlled by the transfer switch. If the transfer switch senses overload via drop in frequency, it drops everything, waits 5 minutes, and brings things back on one at a time...

I have a 22 kW Generac, and I have a similar setup. PSP Products has a 100 amp contactor, complete with enclosure all ready to go. $109 plus shipping and you're good to go. Just FYI, if you're on natural gas, you're going to be lucky to get 60 amps out of a 20 kW. You're also going to lose...

Source: https://www.portal.state.pa.us/portal/server.pt/document/1613738/montly_for_novembermtgcacreport_pdf "PA Turnpike Electric Vehicle ChargingDEP has been working with the PA Turnpike on the deployment of direct current (DC) fast charging stations onthe PA Turnpike. At the last update...

I purchased this 50 foot 14-50 extension cord. It is 6 AWG and works great. I've never even felt it get warm pulling 40A. http://www.homedepot.com/p/Rodale-50-ft-50-Amp-RV-Extension-Cord-with-LED-RV50A50WL/202669075

The issue with the Eaton Chademo chargers is most often the Emergency Stop was pressed by someone. If this is the case, the Emergency Stop mushroom switch must be rotated to release it. Then someone with a key must open the charger cabinet to reset the main 3-phase AC circuit breaker. This...

Whether the price is worth it or not is a valid question, but it's good to know what the options are anyway.

The proper "boost" transformer would be an autotransformer wired in a boost configuration. This means that the primary is wired in series with the secondary. All the current bypasses the primary except for the current required to boost the secondary, and the power through the secondary is...

If you think you can sequence or behavior manage the loads effectively, just add a load shedding control to break the pilot signal in one of the HPWCs in the event you exceed your feeder capacity. This way, if both started to ramp up to max, one would be cut off. Here is an example of a load...