UPS service
Emergency UPS repair, 24/7
When a UPS drops to bypass, raises an alarm it cannot clear or shuts down, the protected load is either running on raw utility power or already off. We dispatch 24/7: same day in Montreal, Quebec City, Toronto and Ottawa, and within 24 to 48 hours elsewhere in Canada. Call or send the model and the alarm text, and we reply with a plan and a quote within 4 business hours, faster for a site that is down.
Key facts
- Inverter failure on a double-conversion UPS: Load transfers automatically to bypass, output not interrupted (Liebert EXM2 manual)
- VRLA battery, 5-year design: Replace at three to four years (Liebert EXM2 manual)
- Battery at 35 °C instead of 25 °C: Service life reduced by 50% (Liebert EXM2 manual)
What happens when you call
- Triage on the phone. We ask for the model, the alarm or display text, whether the load is on inverter, on bypass or off, and what changed before the event.
- Dispatch. A technician is assigned and likely parts are pulled based on the model and the symptom.
- On site. The technician makes the area safe, reads the event log, finds the cause and restores the load to protected power.
- Follow-up. A written report with the root cause, the parts used and what to do so it does not happen again.
What a UPS on bypass means
Most double-conversion UPS systems protect the load by switching to their static bypass when the inverter fails or is overloaded. The Liebert EXM2 manual describes it plainly: in case of inverter failure or an inverter output fuse operation, the load automatically transfers to the bypass and the output is not interrupted.
That keeps the lights on, but the load is now fed by the utility with no battery behind it. The next power cut or sag reaches the equipment directly. A UPS on bypass is an emergency even when nothing is down. Our guide to static bypass and static transfer switches explains the mechanism.
What to do before the technician arrives
- Write down or photograph every alarm and display message before anyone resets anything. The event log is the best clue we have.
- Leave the system in its current state if the load is running. Repeated restarts can turn a bypass event into a dropped load.
- Do not open cabinets or touch battery terminals. DC buses and battery strings stay hazardous with the UPS off.
- Reduce the load if the UPS reports an overload, by shutting down non-critical equipment.
- Check the room: temperature, airflow, signs of water or a burning smell. Tell us what you find.
- If a generator is involved, note whether the event started during a transfer.
Common causes we find
- Battery strings at end of life that collapse under load during an outage.
- Failed cooling fans leading to over-temperature shutdowns.
- Aged DC bus or AC filter capacitors.
- Failed power modules or inverter boards, including on modular systems.
- Overloads after new equipment was added to the protected circuit.
- Upstream protection or wiring faults that look like a UPS failure.
Fault-by-fault diagnosis is covered on our repair page.
Priority response under contract
Sites with a maintenance contract get priority dispatch, and their history, model and battery data are already on file, which shortens the diagnosis. For redundant sites, our N+1 and 2N guide explains how redundancy changes what counts as an emergency.
Hospitals and clinics have their own escalation rules, and service programs built around healthcare facilities spell out how emergency calls are handled there. When the fault turns out to be inside a small unit, repair options for rack and tower UPS are usually the faster route.
Our UPS services
Service by brand
UPS service by city
Engineering guides
Related pages
Common questions
My UPS is on bypass but the load is running. Is that urgent?
Yes. On bypass the load runs on utility power with no battery protection, so the next outage or sag reaches the equipment. Call us before the next power event, not after it.
Can I reset the alarm myself?
Record the alarm text first. A single reset is reasonable if the manual allows it, but repeated resets or restarts can drop the load and erase the clues we need.
How fast can you be on site?
The same day in Montreal, Quebec City, Toronto and Ottawa, and within 24 to 48 hours elsewhere in Canada, around the clock.
Do you repair UPS units no longer supported by the manufacturer?
Often, yes. Parts availability decides it, so we confirm what can be sourced before the visit and tell you if replacement is the safer path.
What should I have ready when I call?
The make and model, the alarm or display text, whether the load is on inverter, on bypass or off, the site address and a contact on site.
Sources, checked October 4, 2026:
- Vertiv Liebert EXM2 User Manual, 100 kVA to 250 kVA UPS, SL-71070 Rev B (06-23), p. 8
- Vertiv Liebert EXM2 User Manual, 100 kVA to 250 kVA UPS, SL-71070 Rev B (06-23), Table 11.1, p. 164
- Vertiv Liebert EXM2 User Manual, 100 kVA to 250 kVA UPS, SL-71070 Rev B (06-23), Table 7.1, p. 115
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