Oof, trying to figure out how to set up power for the new colo rack I need to have up and running quite soon now. (My colo provider has told me they need me to be out of one of my existing racks by the end of this year because they want to put an air handler there, so I'm trying to get a new one set up.)

At the moment I'm looking at:

1. 16A (unless it's 32A, some racks seem to have 32A sockets even if they are only on a 16A breaker) commando plug to plug in under the floor, cabled to a PDU with C19 sockets, enough for one socket per customer I want to meter separately (probably about 3 or 4 to start with).

2. A rack-mounted DIN rail (e.g. https://www.startech.com/en-us/server-management/adjdinkit) with meters mounted on it (e.g.https://www.eastroneurope.com/products/view/sdm230modbus).

3. A bunch of C19-C20 cables, one per meter, which I can cut in half and wire into the in/out of the meters, so their inputs can plug into the upstream PDU (item 1 above) and each have a downstream C20-to-multiple-C13s PDU connected to them, so each customer gets a dedicated PDU and I can meter each one separately.

4. Some twisted pair wire linking all the RS485 modbus connectors of the meters together and connecting to a terminal block with something like https://tripplite.eaton.com/support/U20930NIND at one end of the bus (not sure if I'll need to terminate the other end, or both ends, or if it'll be such a short bus it won't need that).

5. Some software on a server to connect using the USB-RS485 adaptor and talk modbus to the meters to take scheduled meter readings, so I don't have to visit the datacentre (a 4-5 hour round trip now that I've moved!) every month to bill customers.

6. Some method of adding new meters as and when I need them - I think as long as I can wire the new meter to its C19 and C20 tails and physically get at the DIN rail to mount it, and as long as I can add it to the modbus without electrocuting myself, it should be fine. Best way is probably to have 2 twisted pair tails connecting to each meter's modbus port before putting them in, then using terminal blocks to connect them up in a chain, so I don't have to touch the connections on the meter after they are live.

Phew. And one of my customers needs to move into the new rack on 17 November at the latest, because of scheduling. I'm not sure I'm going to have this done in time.

Hmm, I know there are people here who do electrics for a living - does the above look reasonable? I don't see any problems as long as each PDU has a suitable overcurrent protection device built in (most seem to).