Disconnect factory jumper
- Thread starter Pinnie
- Start date
- Location
- New Jersey
- Occupation
- Journeyman Electrician
It's set up for use with DC loads.
What is this?
This is an out of the box 1Ø, 480 volt, 200 amp fused disconnect. Any idea what the #1/0 jumper is for?
forums.mikeholt.com
What is contact interruption distance, and why do dc loads require more?
- Location
- Illinois
- Occupation
- retired electrician
Because there is no zero crossing to help extinguish the arc.
Zero crossing?
An AC voltage rises and falls to zero then goes negative and back to zero as it cycles. Because it goes to zero, arcs are harder to maintain with AC.
The distance an arc can jump is dependent on the voltage, so the faster the switch opens to a greater distance, the quicker the arc is extinguished.
- Location
- New Jersey
- Occupation
- Journeyman Electrician
Maybe someone can explain why it changes something but with that configuration the arc is going across 3 poles instead of just 2.
I see thank you. I’ve not done any higher voltage DC loads. Do you break both the positive and negative leads via the disconnect? Or just the positive?
Breaking both conductors is the equivalent of having twice the distance of just breaking one pole. Or you could break just one but through multiple poles in series. The effect is the same.
gotcha makes sense. Thank you sir!