Sensor R20-AF Fuses

Hi Mike,

The fuses are there for a couple of reasons to do with protection in the event of a short circuit.

1. Protecting the relay contacts. When relay contacts close, if the output is into a dead short the relay contacts can "weld" - basically arc themselves together, either leading to the relay being stuck on or vaporizing the contacts altogether. Fuses open much faster than circuit breakers, so protect against this happening to the relay.

2. Increasing the short circuit protection rating of the module. In the event of a short, all electrical equipment has a rating of how much energy it can withstand, called the short circuit current rating. In a dimmer module, the chokes inherently limit the amount of current that can flow in the event of a fault; in a relay (or CC) module, we provide the fuses to do the same thing.

Hope that helps!

-Tom

Hi Mike,

The fuses are there for a couple of reasons to do with protection in the event of a short circuit.

1. Protecting the relay contacts. When relay contacts close, if the output is into a dead short the relay contacts can "weld" - basically arc themselves together, either leading to the relay being stuck on or vaporizing the contacts altogether. Fuses open much faster than circuit breakers, so protect against this happening to the relay.

2. Increasing the short circuit protection rating of the module. In the event of a short, all electrical equipment has a rating of how much energy it can withstand, called the short circuit current rating. In a dimmer module, the chokes inherently limit the amount of current that can flow in the event of a fault; in a relay (or CC) module, we provide the fuses to do the same thing.

Hope that helps!

-Tom

Yes that help. That all makes sense. Thank you much!

-Mike