Need help with contactor wiring

[rg12]

Am installing a contactor on a large battery project with an Orion BMS and was wandering if:
1. Is there a preference of having the contactor load side control the connection/disconnection of the positive over the negative or vice versa?

2. The marked A1 and A2 main contacts are marked with positive and negative...
What does it mean? it can't be positive and negative as the main contacts control the connection/disconnection of a single wire so it's either the positive OR the negative.

3. The battery side I'm assuming connects to the A1 and the controlled side to A2 right?
Many say it doesn't matter as it's just a switch but I read that in certain contactors there are arc chutes and/or other mechanisms that do have an importance to which way the current flows.

 

[eee291]

Am installing a contactor on a large battery project with an Orion BMS and was wondering if:
1. Is there a preference of having the contactor load side control the connection/disconnection of the positive over the negative, or vice versa?
Usually there are two contactors for negative and positive. IMO, any battery charged above 100V or so should have 2 Contactors. I would put it on the B+ side if I absolutely had to use 1.


2. The marked A1 and A2 main contacts are marked with positive and negative...
What does it mean? It can't be positive and negative as the main contacts control the connection/disconnection of a single wire, so it's either the positive OR the negative.
Don't know what contactor you have, it probably just means it can be installed on either - or + side.

3. The battery side I'm assuming connects to A1 and the controlled side to A2, right?
Many say it doesn't matter as it's just a switch, but I read that in certain contactors there are arc chutes and/or other mechanisms that do have an importance to which way the current flows.
Again, don't know what contactor you have, and it doesn't matter which way current flows, the chute suppresses the ark either way. If you're expecting a high load disconnect that the contactor can't handle, then it might be wise to add a fuse...

 

[rg12]

Am installing a contactor on a large battery project with an Orion BMS and was wondering if:
1. Is there a preference of having the contactor load side control the connection/disconnection of the positive over the negative, or vice versa?
Usually there are two contactors for negative and positive. IMO, any battery charged above 100V or so should have 2 Contactors. I would put it on the B+ side if I absolutely had to use 1.


2. The marked A1 and A2 main contacts are marked with positive and negative...
What does it mean? It can't be positive and negative as the main contacts control the connection/disconnection of a single wire, so it's either the positive OR the negative.
Don't know what contactor you have, it probably just means it can be installed on either - or + side.

3. The battery side I'm assuming connects to A1 and the controlled side to A2, right?
Many say it doesn't matter as it's just a switch, but I read that in certain contactors there are arc chutes and/or other mechanisms that do have an importance to which way the current flows.
Again, don't know what contactor you have, and it doesn't matter which way current flows, the chute suppresses the ark either way. If you're expecting a high load disconnect that the contactor can't handle, then it might be wise to add a fuse...

Why would there be a need for 2 contactors?
I have one for charge and one for discharge, both rated 1000VDC for a system that is fully charged at 705V