Breaker

[tuberider]

Is a 20amp double pole breaker the same as two 20amp single pole breakers put together

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[St. Elsewhere]

They only differ if the two single pole breaker toggles are not mechanically connected. If connected, when either of them trips, both will go to the off position.

[tuberider]

Thank you very much

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[PaulinOz]

Do not forget to specify AC or DC as well, they are not the same.

[tuberider]

What is the difference between ac and dc breakers

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[exMaggieDrum]

I could be wrong but, in the US at least, most boat breakers work for either AC or DC. You would use a double pole double throw breaker for your AC master switch at the AC in and on the panel. You would need only a single pole breaker for the DC master, but the breakers are rated the same.

[PaulinOz]

Read the full manufacturers specification of the breaker you want to use, an item rated at 110/240 volts AC might only be good for 24 volts DC. Which may or may not be suitable. Just because something is good for high voltage AC, it is not automatically good for a lower voltage DC.

[smac999]

no they are not the same. they are intereconnected internally as well as externally. you can't just buy 2 singles and join the handles.


most of the marine breakers IE bluesea are rated both DC and AC

[St. Elsewhere]

Originally Posted by smac999

no they are not the same. they are intereconnected internally as well as externally. you can't just buy 2 singles and join the handles.

The typical marine circuit breakers such as Blue Sea devices have no internal interconnections. The photo below is a similar desgin.

Common trip breakers




Three-pole common trip breaker for supplying a three-phase device. This breaker has a 2 A rating


When supplying a branch circuit with more than one live conductor, each live conductor must be protected by a breaker pole. To ensure that all live conductors are interrupted when any pole trips, a "common trip" breaker must be used. These may either contain two or three tripping mechanisms within one case, or for small breakers, may externally tie the poles together via their operating handles. Two-pole common trip breakers are common on 120/240-volt systems where 240 volt loads (including major appliances or further distribution boards) span the two live wires. Three-pole common trip breakers are typically used to supply three-phase electric power to large motors or further distribution boards.
Two- and four-pole breakers are used when there is a need to disconnect multiple phase AC, or to disconnect the neutral wire to ensure that no current flows through the neutral wire from other loads connected to the same network when workers may touch the wires during maintenance. Separate circuit breakers must never be used for live and neutral, because if the neutral is disconnected while the live conductor stays connected, a dangerous condition arises: the circuit appears de-energized (appliances don't work), but wires remain live and some RCDs may not trip if someone touches the live wire (because some RCDs need power to trip). This is why only common trip breakers must be used when neutral wire switching is needed.

[Colin A]

I haven't tried to take a Blue sea breaker apart lately but I can tell you the carling A series are interconnected internally when ordered in multiple pole configurations. Given that Blue seas buys from Carling my guess is they are too. If you take out the handle connections it won't let you turn them on on one at a time all poles trip at the same time.

[Matt Johnson]

Originally Posted by Colin A

I haven't tried to take a Blue sea breaker apart lately but I can tell you the carling A series are interconnected internally when ordered in multiple pole configurations. Given that Blue seas buys from Carling my guess is they are too. If you take out the handle connections it won't let you turn them on on one at a time all poles trip at the same time.

100% correct. I just tried a Blue Seas double pole, and you cannot trip unless both handles go at the same time.

Matt

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