New electrical wiring using existing breakers and panel.

[katwalatapan]

Hello,

I am trying to plan a renovation project. The existing site has a 225 A, 3-phase, 120/240V main electrical panel with breakers serving lighting, receptacles, heating equipment, HRV, etc.

The existing receptacles, lighting, heating equipment are being removed with their existing wiring and new ones are to be installed in different locations.

I wanted to inquire if using existing breakers for new wiring and load makes more practical sense or specifying new electrical panel with new breakers? The loads after the renovation are still pretty much the same as existing loads. I would appreciate your comments on any situations that I should look into for such renovation project.

Thank you.

 

[ScottyUK]

'It depends'.

To consider:
[ul]
[li]How old and in what condition is the panel? Is it still supported by the manufacturer?[/li]
[li]How critical are the loads it serves?[/li]
[li]What fraction of the cost of the overall job is a new panelboard? In countries where labour is cheap and material expensive you will evaluate this differently to one where materials are relatively cheap and labour is expensive.[/li]
[/ul]

 

[katwalatapan]

Thank you very much for the response.

The panel is in quite decent condition. The loads are heating and air handling loads, but nothing life safety, so not too critical. In Canada, I would say materials are relatively cheaper than the labour.

 

[cherryg]

Usually in renovation projects, new loads appear from nowhere. Hence one good check is to see how any spares/spaces are there in the existing panel. Since the new loads are at presumably at new locations, and the existing breakers will only support termination up to certain size, you can conduct simple voltage drop calculation to see if there is any increase in your cable size. Also, do remember that the earlier wires were designed as per the old CEC at 90 deg C temp., and you have to size the cables for 75 deg C i.e there may be some cable size increase.

 

[cherryg]

If a bulk of your new loads are located at a different location, away from the panel, it would be prudent to feed another panel from this panel. It can be a single phase feed or a three phase feed (depending on your load; in case of three phase feed, you need a three pole breaker which means retrofitting in the existing panel, unless you already have a three phase breaker).