IT Rack - electrical circuit for UPS

[Darrensen]

Hi all,

I'm putting together a small IT rack for a client and i'm looking for multiple opinions on what electrical circuit to install.

Essentially, all of the equipment will be powered from the UPS. APC Smart-UPS750A
https://www.apc.com/shop/hr/en/prod...D-RM-2U-230V-with-SmartConnect/P-SMT750RMI2UC

There isn't a great deal of equipment in the rack.
VDSL Modem
Firewall
24 port poe switch
UPS

Obviously it needs to be on a separate loop to everything else. But i'm wondering what amp to specify. 16amp would probably be fine or is that a bit overkill? Any sparky's out there that can give any advice?

Many thanks

 

[neil_g]

A 750 with that small load will be fine from a standard 3 pin 13A outlet.

 

[BongoHunter]

What's the model of the POE switch? Some are real power hogs if pushing power through a lot of ports.

How long do you want to run for without power? Or its this just protection for momentary blips rather than many minutes without power?

 

[Darrensen]

Thanks for your replies.

I'll be using Unifi switch gear.

 

[Caged]

Just put a 20A radial in, two double sockets marked up for IT use.

 

[K.C. Leblanc]

Just put a 20A radial in, two double sockets marked up for IT use.

It might be an idea to have it on a dedicated RDC (or more likely RCBO). This will reduce the risk of a fault on a different circuit causing an outage. If it's in an accessible location you might want to consider getting the electrican to wire a kettle lead into a fused spur instead of using a traditional socket. That way you won't get some congenital idiot unplugging it to plug in their phone charger (hopefully!).

 

[Caged]

That's what a radial is. The IEC connector is a horrible design and falls out when you breathe near it, there's no need to put weird non-standard outlets in place as anybody who is daft enough to unplug a server rack to try and charge a phone is going to do the same thing with a kettle lead before staring at it and realising that it doesn't fit. If there's a real fear of people unplugging things and replacing the staff isn't an option then use those outdoor sockets that have a cover that you can lock in place.

 

[K.C. Leblanc]

That's what a radial is.

Nope, while an individual circuit will have it's own circuit breaker to provide over current protection it's common for the RCD protection to be shared between several circuits. This is less then ideal since a fault can cause several circuits to trip out.

The IEC connector is a horrible design and falls out when you breathe near it, there's no need to put weird non-standard outlets in place as anybody who is daft enough to unplug a server rack to try and charge a phone is going to do the same thing with a kettle lead before staring at it and realising that it doesn't fit. If there's a real fear of people unplugging things and replacing the staff isn't an option then use those outdoor sockets that have a cover that you can lock in place.

Given that the UPS that the op is intending to use has an IEC connector he's not going to avoid using one. What I was suggesting was having an IEC tail wired straight into an fused spur unit, so not easy to unplug.

 

[Caged]

I assumed if I asked someone to install a new circuit for IT use that it would be on its own RCBO but yes you may want to specify it.

I know what you're saying about the IEC lead in a flex outlet plate but I'd still recommend against it. It limits your options in future (e.g. if you buy a UPS with a C20 inlet or want to add a mains PDU into the mix that doesn't pass through the UPS) and if the lead gets damaged then you need to get an electrician involved to swap it.

I've done the whole IEC sockets everywhere in a server rack thing in the past and I just loathe the connector. The sockets aren't too bad but the plugs that go into PDUs are awful, so people end up doing non-standard workarounds like having locking connectors.