mstrlucky74
Senior Member
- Location
- NJ
Engineer asking us to remove 100A MCB in panel and make panel MLO. Is that a PIA? What's involved? Thanks.
Get the drawings from the gear rep and have him price modifications
If it is just a panelboard why would you need to have the gear rep price it up?
I think most times it is pretty simple to remove the MCB in most PBs but you also have to close the hole where it used to be.
You have to attach the main lugs to the phase buses, no?
Engineer asking us to remove 100A MCB in panel and make panel MLO. Is that a PIA? What's involved? Thanks.
If it is just a panelboard why would you need to have the gear rep price it up?
I think most times it is pretty simple to remove the MCB in most PBs but you also have to close the hole where it used to be.
Can be as simple as removing a 3 pole circuit breaker, bolting on 3 terminals and installing blanks over the 3 slots. Why is he requesting this in the first place?
What hole?If it is just a panelboard why would you need to have the gear rep price it up?
I think most times it is pretty simple to remove the MCB in most PBs but you also have to close the hole where it used to be.
What hole?
The others have addressed the "how to." I will speak to the "whether or not to." Who wants this done and why? More to the point, is there a breaker upstream of this panel that serves as the overcurrent protection for the panel and its feeder?
The panel in question was being fed via 45kva xfrmr. Now the 45kva xfrmr is feeding a new panel and a 3P 100A breaker in the new panel is now feeding this panel in question. Not sure if the pick is legible. The panels with the square and #1 are the one swapping from MCB to MLO.
Apparently your main distribution board was able to accept those breakers, not always the case. Even if the same breakers you may possibly still need some additional hardware to install them such as bus links and fasteners that were designed/tested for the application vs common fasteners.Once I finished a job that someone else started. They had ordered the 4 250 amp panelboards with main breakers. They were subs and not fed by taps or tranny's so there was no need for the mains. I took them out, added lugs, and used the breakers in the main distribution board which hadn't been ordered yet. Saved the client $1500 I think. But if you don't have specific repurpose for the breaker, it's probably not worth taking out.
Apparently your main distribution board was able to accept those breakers, not always the case. Even if the same breakers you may possibly still need some additional hardware to install them such as bus links and fasteners that were designed/tested for the application vs common fasteners.
Not that you can't get such hardware, but these manufacturers seem to like to honk you hard on such items if a stand alone purchase, yet practically give a lot of stuff away in comparison when you order the entire panel and accessories on one order.
Need 1/2 dozen I-line breakers, maybe even as little as 3 or 4? Might get a small main lug panel plus your 3-6 breakers for less cost than if you purchased just the 3-6 breakers. That is how they like to sell this kind of product.
Many gear manufacturers will sell you complete new panel, cabinet, breakers and needed accessories for less $$ than they would sell you just a few of the components alone. Keep that in mind when deciding what to do.
I found this out recently when reviewing shop drawings for a job. I had called for replacing a bunch of circuit breakers in an NF panel. The shops showed a whole new panel. Naturally, I was a bit concerned that something was going on that I knew nothing about, but the contractor told me buying a whole new panel, new breakers and all, was significantly less than just buying the breakers.
I found this out recently when reviewing shop drawings for a job. I had called for replacing a bunch of circuit breakers in an NF panel. The shops showed a whole new panel. Naturally, I was a bit concerned that something was going on that I knew nothing about, but the contractor told me buying a whole new panel, new breakers and all, was significantly less than just buying the breakers.