UPS service
UPS repair and fault diagnosis
We diagnose and repair UPS systems on site: alarms that will not clear, failed power modules and boards, cooling and capacitor failures, and older ferroresonant units. Every repair starts with the event log and ends with a written answer on whether the unit is worth fixing. We reply and quote within 4 business hours, and work across Canada with same-day dispatch in Montreal, Quebec City, Toronto and Ottawa.
Key facts
- Module replacement on Galaxy VS: Live Swap, no scheduled downtime (Schneider Electric)
- Bus capacitor replacement: Every six years (Liebert EXM2 manual)
- Fan replacement: Every six years; estimated life not less than seven years (Liebert EXM2 manual)
What we repair
- Alarms and fault codes that recur or will not clear, read against the manufacturer's documentation for that model.
- Power modules, rectifiers and inverters, including hot-swappable modules on modular systems.
- Control and interface boards, displays and network cards.
- Cooling fans and the over-temperature faults they cause.
- DC bus and AC filter capacitors, replaced as a set.
- Static switch and bypass faults.
- Ferroresonant UPS, a transformer-based design still found in industrial and utility sites.
How a repair visit runs
- Event log first. We download the alarm history before changing anything. It shows what failed first and what followed.
- Isolate the cause. A UPS alarm often points at a symptom, such as a battery or overload message, while the cause is upstream, in the room or in another component.
- Repair or make safe. Parts carried for the model are fitted on the spot; others are sourced and the system is left in its safest state, usually on maintenance bypass, until they arrive.
- Prove it. The unit is returned to normal operation and tested under load.
Modular systems: repairs without downtime
On modular designs a failed power module can often be replaced with the load running. Schneider Electric describes the Live Swap feature of the Galaxy VS as third-party verified module replacement with no scheduled downtime. On non-modular systems, the load is moved to maintenance bypass for the repair. We plan that transfer with you, because the load runs without battery protection while it lasts.
Repair or replace?
Some faults are cheap to fix and some are the first sign of a unit at the end of its life. We weigh four things and put the answer in writing:
- the age of the unit and of its capacitors, fans and batteries;
- whether parts are still available from the manufacturer or the secondary market;
- the cost of the repair against the remaining service life;
- whether the load has grown past what the unit can carry.
When replacement wins, our end-of-life planning page and the guide to replacing a discontinued three-phase UPS cover the next steps.
Ferroresonant units
Ferroresonant UPS systems regulate voltage with a saturating transformer rather than a high-frequency inverter. They are heavy and simple, and many have run for decades in plants, utilities and telecom sites. We test and repair them, replace their batteries and capacitors, and help plan the move to a current design when parts run out.
Large systems in mission-critical rooms often justify a deeper review of the platform itself; this look at high-capacity three-phase UPS for critical infrastructure sets out what to compare. For small units, a bench repair service is usually cheaper than a site visit.
Our UPS services
Service by brand
UPS service by city
Engineering guides
Related pages
Common questions
Can you repair a UPS the manufacturer no longer supports?
Often. It depends on parts. We check what can be sourced for that model before the visit and tell you plainly if the repair is not worth it.
Do you have to shut down the load to repair the UPS?
Not always. Modular systems can often swap a module with the load running. Other systems are moved to maintenance bypass first, which keeps the load on but without battery protection.
Why does my UPS show a battery alarm when the batteries are new?
The alarm may come from the battery monitoring, the charger, a connection or a setting rather than the batteries themselves. That is why we read the event log before replacing anything.
Do you repair single-phase UPS?
Yes, when it makes economic sense. For small units the answer is often a new battery or a replacement unit, and we will say so.
What information speeds up a repair quote?
The make, model and serial number, the alarm text, the age of the batteries and a photo of the display. That lets us bring the right parts on the first visit.
Do you repair ferroresonant UPS?
Yes. We test, repair and re-battery ferroresonant units and help plan their replacement when parts are no longer available.
Sources, checked October 4, 2026:
- Schneider Electric Canada, GVSUPS20KFS product page (Galaxy VS UPS 20kW 208V for External Batteries, Start-up 5x8)
- 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
Send us the details
Fill this in and your own mail client opens with everything already written out. Nothing is sent from this site.
Brand names are trademarks of their owners and are used only to identify the equipment we service. We are not the manufacturer and are not affiliated with it.