Beta 3 service manual · Power
1U UPS
The 1U UPS is a rack battery. It feeds what is plugged into it, and keeps feeding it when the power behind it is lost.
| Category | Power distribution and battery |
|---|---|
| Rack height | 1U |
| Price | $350 |
| Rating | feeds 1,000 W |
| Ports | IN, OUT1 to OUT5, CTL |
Charging
A UPS charges only while it is plugged into live power and switched on. Powered on but unplugged, it slowly runs itself down. A switched-on PDU on its outlets draws a few watts even with nothing plugged in, so a battery always drains under one.
When the feed is lost
Each rack UPS is its own battery. It backs only what is downstream of it, and it drains at its own load: a heavy load empties it faster. It carries its downstream whenever its feed is lost: an unpaid bill cuts the grid, a circuit trips, a lead is pulled, or the PDU above it is switched off.
Stack units for more time. A chained unit passes power through and holds its charge until the one above it empties. When a battery reaches 0%, everything on it goes down.
Reading the face
- The BATTERY gauge shows ten charge segments and the state: ONLINE, CHARGING, or ON BATTERY with the minutes left.
- The LOAD bargraph runs into the red near capacity.
- Every outlet has its own load bar.
Why it matters
- Client contracts can ask for battery minutes behind every earner.
- A cron job set to run
on outageonly runs if the terminal server sits behind a UPS. - A grow bed fed from a rack UPS keeps its lamp through a grid cut.
The main room also has a house UPS on the floor, with a few sockets of its own. It is a separate unit: see UPS and batteries.
See also: 1U PDU · UPS and batteries · Bills and outages.