Is this one of those panels where one of the double pole breakers shuts off other breakers below it? The six throw rule or whatever it was called?
I'm wondering how to shut this off completely for a) emergencies b) checking circuits.
It looks full. I'm also wondering if I should upgrade it to a newer panel?

 

It helps if you insert images large enough to be easily seen. https://www.doityourself.com/forum/l...rt-images.html

 

Click on the image. I'm on mobile and it doesn't allow me to use the DIY upload process.
https://s1.postimg.org/2mhv8a016n/20171105_195712.jpg

 

The wiring diagram inside will show whether this is a split bus panel.

 

I would normally switch off the main breaker before opening the panel. How do I do that on this? The bus, although I won't be touching it, will still be live.

 

Doesn't look like a split bus as most have a gap between upper and lower breaker sections. Check to see if there is a disconnect upstream/at meter.

Also - none of the double pole breakers appear to be labeled for a "lighting" section.

 

Why would the lighting be on a double pole? Always thought lighting was single pole 15a circuits?

 

Can't really tell from looking at the cover. I'm suspicious that it might be a split bus, which means there isn't really a main disconnect. It might be a main lugs panel, in which case there may be a disconnect or fuse upstream, perhaps built in to the meter.

 

I believe Commander is the Canadian version of Challenger. I would put my money on finding a disconnect breaker near the meter.

 

With a split-bus panel the bottom lighting section(s) is fed by a double pole breaker in the top section. Lots of times 60 amp.

 

Not all split bus panels have a gap between the mains and the branch circuit breakers.

 

The submaster breaker for the bottom section of a split bus panel is sometimes referred to as the "lighting" breaker. At any rate all of the breakers should be labeled.

Like in a panel with a single master breaker up top, the bottom part of the split bus panel is split between the two legs of the 120/240 volt service so the "lighting" breaker will be a two pole breaker.

Lights and small appliances will not (may not) be connected directly to a circuit coming into the top half of the split bus panel unless the breaker up there for that circuit is 20 amps or less (usually compromises the flexibility of the panel) or unless there is a subpanel downstream on that circuit.

A panel that is not a split bus panel and that does not have a master breaker up top is called a lug panel. If it has more than six breakers, then it must have a master breaker rated for the panel amperage rating somewhere, for example at the meter if the feed comes directly from there.

 

There was a main disconnect on the other side of the wall of the main entrance wires/meter.
however, this is rated 100A and the sub panel is rated 125A

 

.
That is fine. The sub panel is rated higher then what it is fed with. If it was a 70 amp panel that was protected by a 100 amp breaker you would have an issue.