CTL twins or not?

[Coppersmith]

I'm going to be replacing all the breakers in a 40+ year old Square D QO panel. It currently has several twins. Should I assume that only non-CTL twins will fit in there?

 

[LarryFine]

I wouldn't. Assume, that is.

You may be able to rely on the panel door drawing or model number, but I would visually check the stabs.

 

[James L]

I would take enough of each, just in case.
CTL will save you money

 

[Coppersmith]

Unfortunately, I've only seen the panel in a couple of blurry phone pictures. I don't want to show up with CTL's and have them not fit. I also don't want to pay more than I need to for breakers. Considering the shortage of breakers right now, I'm concerned about getting any breakers at all.

 

[James L]

Unfortunately, I've only seen the panel in a couple of blurry phone pictures. I don't want to show up with CTL's and have them not fit. I also don't want to pay more than I need to for breakers. Considering the shortage of breakers right now, I'm concerned about getting any breakers at all.

That's why I say take both.
Return the ones you don't use

The most efficient use of your time is to have everything you need to do the job in one trip.

Go loaded for bear

Then you don't even need to waste a trip on returning materials. Just take them back when you're going to be getting other stuff.

 

[jim dungar]

I'm going to be replacing all the breakers in a 40+ year old Square D QO panel. It currently has several twins. Should I assume that only non-CTL twins will fit in there?

Square D panels have been CTL style for the past 60 years or so.