Can I use a Common Trip breaker to replace my QT Q23030 Quad breaker that says no common trip on the label

Question

Can I use a Common Trip breaker to replace my QT Q23030 Quad breaker that says no common trip on the label. The breakers are in a 1995 Double wide mobile home and is labeled as DRYER. I don't know if it makes difference if I use a common trip and no common trip Breaker.

Answer 1

There is the unknown of: why replace it at all?

But assuming there is a good reason to replace it (e.g., physical damage) and assuming it is the correct breaker for the panel (which is not always the case), yes replacing a non-common trip quad with a common trip quad is perfectly fine.

Common trip on a pair of breakers means that if one trips then the other does at the same time. That is required in certain situations, but other than possible nuisance trips, it does not hurt if you have common trip when you don't need it. A classic example is a Multi-Wire Branch Circuit (MWBC). An MWBC generally (there are certain exceptions) does not require common trip but does require common shutoff. Any double-breaker with common trip also has common shutoff. But this quad breaker is an example where (from the examples I've found online) the inner pair has common trip and the outer pair does not.

The other big question is why do you have a quad 30? A 30A pair is quite common for a water heater, oven or other large appliances. A quad 30A used for two such appliances is relatively unusual, and in that case generally you would have common trip on each pair rather than just the inner pair. If you have a quad with 30A common trip on the inside and 20A non-common-trip on the outside for two 120V circuits, that would make a lot of sense. So that leaves me wondering whether this particular breaker is the right one for your specific use.

Answer 2

In some situations a "handle tie" is sufficient, but in others, "common trip" is required by code. Common trip could be thought of as "handle tie plus." Handle tie forces both sides of a 120/240 circuit to be turned off at the same time for maintenance, and is acceptable for a 240-volt-only load (a water heater or electric baseboard, for example) or for a multi-wire branch circuit (MWBC) serving only 120 volt loads. Common trip is required for a 120/240 dual-voltage loads such as an electric range or clothes dryer. (See DIY and Mike Holt. Both refer to NEC 240.15(B)(1)&(2).)

In general, so far as I could determine, it's always acceptable to use a common-trip where only handle tie is required. On that alone we can answer your question as "yes." However, given that yours is labeled as feeding a dryer, it almost certainly is required to be common trip and whomever put a handle-tie model in there made an error.