UPS Cable Type

[DM2-Inc]

I'm working on a 24 VDC UPS, 1600 Amp Hour, 75Amp system.

I'm trying to find out what type of cable I need to be using.

There will be 5 trays of batteries and each tray will have a maximum current draw of 15 Amps. Each tray will be fused at 20Amps. Each tray will have 4, 100 Amp VLRA batteries.

The wiring from the UPS to the Fire Panel will be a single pair, with a maximum current of 75 Amps and will be fused at 100 Amps.

I intend to size the cable for each tray to handle 25 Amps min., and from the UPS to the Fire Panel, for 125 Amps min.

I've looked at article 700, 701, and 702 for some hints on the type of cable but can't seem to find any.

Anybody experience with UPS's and the types of cables?
Do you see anything wrong with the logic on how I intend to size the cables?

Regards

 

[gadfly56]

What the heck kind of fire alarm control panel do you have?? :-? The OCPD for fire alarm panels at 120VAC is limited to 20 amps.

 

[DM2-Inc]

This is a Fire & Gas detection system. There are 5 of these systems and this is the smallest of the 5 (only 1600 Amp Hours). The others are 2000 Amp Hours. There are some 300 flame and gas detectors, along with other sundry devices (Deluge, Manual Pull Stations, Speakers, Strobes, etc.), in the field.

The UPS is a redundant system (i.e. two 75 Amp Power Supplies), 208 VAC (keeps the breaker below 20 Amps), and the controller is SIL2.

 

[weressl]

I'm working on a 24 VDC UPS, 1600 Amp Hour, 75Amp system.

I'm trying to find out what type of cable I need to be using.

There will be 5 trays of batteries and each tray will have a maximum current draw of 15 Amps. Each tray will be fused at 20Amps. Each tray will have 4, 100 Amp VLRA batteries.

The wiring from the UPS to the Fire Panel will be a single pair, with a maximum current of 75 Amps and will be fused at 100 Amps.

I intend to size the cable for each tray to handle 25 Amps min., and from the UPS to the Fire Panel, for 125 Amps min.

I've looked at article 700, 701, and 702 for some hints on the type of cable but can't seem to find any.

Anybody experience with UPS's and the types of cables?
Do you see anything wrong with the logic on how I intend to size the cables?

Regards

Some UPS manufacturers have changed their wiring from standard Class B stranded copper to high strand-count flexible copper - like SIS, DLO, etc. - type cables with compression connectors for higher reliability.