Challenger SB20(40-40)CT

[DLP1911]

I’m bidding a job that has a Challenger panelboard SB20(40-40)CT. It’s full. If this model# is like square D, then it means 40 space-40 circuits, aka no tandem/piggy backs allowed.
Anyone know for sure? Not real familiar with Challenger products. Help appreciated. I told the customer we need to add a sub panel, he said another contractor told him he would add tandems

 

[kwired]

There may be non-CTL tandems available that will fit, but that won't comply with the listing and instructions.

 

[AC\DC]

Any light loaded circuits like lighting you can pigtail together. Since everything is led now it’s pretty easy to find them. Free up enough space for a 2-pole