Five installation essentials — miss one and it fails
Installing a UPS is not a matter of finding a socket. Get any one of these five points wrong and the result ranges from nuisance alarms and shutdowns to damaged equipment and a safety hazard left behind.
1. Is there enough incoming capacity?
A UPS output is always less than or equal to its input. If the incoming supply is undersized, the input breaker will trip when the UPS returns from battery mode to mains, or when it charges and supplies the load at the same time.
Before work starts, confirm the incoming breaker rating, the cable size, and whether any other high-power equipment shares that circuit.
2. Distribution and breaker arrangement
- The UPS input and output should each have their own independent breaker protection.
- Output circuits should be grouped by load, so that any one can be isolated later for maintenance.
- Fit a bypass: during service or a fault you can switch to direct mains supply without stopping the business.
- Add surge and lightning protection, particularly in older buildings or where lightning exposure is poor.
3. Earthing and phase rotation
- Earthing is the safety floor. Poor earthing leaves the enclosure live, disrupts equipment communications, and removes your protection during a fault. Earth resistance should be measured before work starts.
- Phase rotation must be confirmed. If a three-phase UPS is wired in the wrong rotation, it will usually refuse to start with an alarm, or run its fans backwards and behave erratically.
- Avoid earth loops. Multiple earth points around a room can form a loop and introduce interference, so earthing has to be planned as a whole rather than unit by unit.
4. Ventilation and cooling — the one most often missed
Battery life is directly tied to temperature: for every 10 °C rise in ambient temperature, the ageing rate of a lead-acid battery roughly doubles.
In practice, make sure there is enough cooling space in front of and behind the cabinet, that air inlets and outlets are not blocked, that room air conditioning runs at night and at weekends too, and that the equipment is kept away from heat sources and direct sun.
Many "why did the batteries fail after two years" cases turn out, on inspection, to be a cooling problem rather than a product-quality problem.
5. Battery cabinet floor loading and space
A battery bank concentrates a significant weight. Before installation, confirm:
- whether the floor loading is sufficient (especially in older buildings, mezzanines and converted units)
- whether there is a transport route in (lift dimensions, door width, stair corners)
- whether the cabinet position allows testing and whole-string replacement later
Where space and floor loading are tight, a lithium iron phosphate battery pack is usually the more workable choice — noticeably smaller and lighter at the same capacity. The units are listed in our lithium packs.
The five most common installation mistakes
- Mixing new and old battery blocks, so the whole string ages faster.
- Not enough cooling space, so the batteries fail early.
- No bypass, so future maintenance means a shutdown.
- Poor earthing, leaving the enclosure live or the communications disturbed.
- Ignoring start-up inrush, so the unit alarms on overload the moment it is switched on.
None of these five is advanced engineering, but all of them have to be thought about before the work, not after. Putting them right afterwards almost always costs far more than doing it properly once. If you would rather have it surveyed first, talk to us.