Input Supply Requirements

[Anonymous user]

I'm currently running a Smart-UPS 3000 RM XL to power 5 servers, networking and telecoms equipment.
Load is reported to be about 50% Watts just now with what is probably average server usage.
The APC requirement calculator, put it at 2200W required for all the equipment.

Input is via a C19 to BS1363A power cord.
The circuit breaker supplying the socket that the UPS is attached to is a C20

I'm considering putting in a second 3000VA UPS (SMX3000RMHV2U) in order to split the load and provide a bit of redundancy for the servers with dual power supplies
I'm also looking to add an additional battery to the new UPS to give longer runtime.

Am I likely to run into any problems with connecting the two 3000VA UPS devices to the same circuit breaker?

Any advice would be much appreciated.

Thanks

[BillP]

you'll have to check on your local electrical code but a UPS is designed to be connected to a dedicated circuit. you will need to worry about overloads on the circuits and the potential for tripping breakers. so by general practice, this is not a good idea.

C19/C20's are rated for 20A. you need to make sure between the two units you don't exceed the ratings of the the circuits. in North America, circuits are de-rated by 20% so 20A isnt supposed to exceed to 16A so you have a 4A buffer for safety reasons but i don't know if it works the same in your region.

[Anonymous user]

thanks for the reply.

I suppose my question now is..
what is the load drawn through the breaker by the the UPSs likely to be?
If I'm saying that they will be supplying 2200W worth of equipment - what overhead will the UPS add.

my maths suggests that running 2200W of equipment @ 230-240V will be ~10A

The current UPS is the only device connected directly socket the breaker is supplying.

[BillP]

you can expect with fully discharged batteries, the UPS itself may draw up to 275-300 watts of power in addition to what it needs to power your load.

[POsorio_apc · Accepted solution]

Considering your scenario I also recommend that you purchase a ATS (Rack-Mount Transfer Switch) to be connected with the 2 UPS to protect all the devices with only one power supply (for example: switch, router, etc).

Something like this: http://www.apc.com/products/resource/include/techspec_index.cfm?base_sku=AP7721

In this scenario (w/ ATS) if you have any problem with one UPS the other one will secure all the equippments with one power supply only.