Mitsubishi · 9900D
Mitsubishi 9900D three-phase UPS
The Mitsubishi Electric 9900D is a high-density three-phase UPS for large data centres rated 1,200 to 2,000 kVA at 480 V.
Mitsubishi Electric 9900D: key facts
Mitsubishi Electric lists the 9900D as current.
- TypeHigh-density three-phase UPS for large data centres
- Power range1,200 to 2,000 kVA at 480 V
- North American voltages480 V
- StatusCurrent
- Service in CanadaPreventive maintenance, battery replacement and emergency repair, including discontinued units. 1 (438) 881-3363
Sources, checked October 3, 2026: Mitsubishi Electric, 9900D 1-2 MW.
What does a Mitsubishi 9900D fault code mean?
3:18. On a Mitsubishi 9900D, a code with A as its second letter is an alarm and a code with F is a failure; U means the bypass module raised it, M means a UPS module did. This video walks the overload, supply, battery, failure and switch codes operators see most, with the manual's own guidance lines, from the 9900D owners and technical manual U-ENM00055 Rev 7, section 7.0.
Chapters
- 0:00 How do you read the fault codes on a Mitsubishi 9900D?
- 0:23 What does the display show?
- 0:42 Which overload alarms will you see?
- 1:03 What about the supply codes?
- 1:30 Which battery codes matter?
- 1:58 And the failures?
- 2:20 What can you check safely?
- 2:42 Two switch codes worth knowing
- 2:59 Request a quote
Transcript
0:00 How do you read the fault codes on a Mitsubishi 9900D? How do you read the fault codes on a Mitsubishi 9900 D? A code with A as its second letter is an alarm, and a code with F is a failure. U means the bypass module raised it, and M means the UPS module did. A Major failure moves the load to the static bypass line; with a Minor failure the UPS keeps running, but the cause still has to be found.
0:23 What does the display show? What does the display show? Next to the code, it shows a status message and, for most codes, a guidance line such as decrease load, or call service engineer. Before anything is reset, write down the code, the message and the time. The manual asks for that record first, and it is what a technician needs to read the event log.
0:42 Which overload alarms will you see? Which overload alarms will you see? UA805, Overload, means the output load current is above 100 percent of rated current, and the guidance is decrease load. UA807, Inverter Overload, means the load current is between 105 and 149 percent of rated current.
1:03 What about the supply codes? What about the supply codes? UA812, Bypass Voltage Out Of Range, means detection below 87 or above 112 percent. UA813, Bypass Phase Abnormal, means the bypass conductors are not in the proper phase sequence, and an electrician checks that wiring. UA815, Transfer Prohibition, means the bypass is abnormal, so avoid any planned transfer until it is back.
1:30 Which battery codes matter? Which battery codes matter? UA824, CB 2 Open, means the battery breaker is open; the guidance is turn on CB 2, and until someone trained closes it, there is no battery backup. UA834, Battery Depleted, means the battery voltage has reached the depleted level: call a technician. UA866, Battery End Warning, means prepare the loads for shutdown if the outage continues.
1:58 And the failures? And the failures? UF258, Load Abnormal, means the load was transferred for overload more than 4 times within 5 minutes, so leave the load where the UPS put it and call. UF162, Battery Abnormal, is a failure found by the battery self-check. Most failure codes carry the guidance call service engineer.
2:20 What can you check safely? What can you check safely? Write down the code, the message and the time before anything is reset. Reduce the load: most overloads follow a change on the protected side. Check whether the utility had an event, whether a generator is running, and whether electrical work was done upstream. A phase sequence error after such work is a wiring correction for an electrician.
2:42 Two switch codes worth knowing Two switch codes worth knowing. UA817, Emergency Stop Activated, means the EPO switch or an external contact triggered it: find out who or what before any restart. UA830, Interlock Switch On, usually means maintenance is underway.
2:59 Request a quote If you are servicing a 9900 D, request a quote at threephaseups.ca.
How a three phase double conversion UPS carries the load, and where the bypass sits.
9900D models
The orderable configurations we supply and service:
| Model | Rating | Phase / Voltage | Part number | Status |
|---|---|---|---|---|
| Mitsubishi 9900D 1200kVA | 1200 kW | 3ph in/out 480V | · | Current |
| Mitsubishi 9900D 1250kVA | 1250 kW | 3ph in/out 480V | · | Current |
| Mitsubishi 9900D 1500kVA | 1500 kW | 3ph in/out 480V | · | Current |
| Mitsubishi 9900D 1600kVA | 1600 kW | 3ph in/out 480V | · | Current |
| Mitsubishi 9900D 2000kVA | 2000 kW | 3ph in/out 480V | · | Current |
Specifications
Megawatt density & verified performance
The 9900D is a 480 V UPS in five ratings (1200, 1250, 1500, 1600 and 2000 kVA) that Mitsubishi describes as the first 2 MW system to market. Its modular design lets supplemental modules be added over time, using the original bypass module, with optional N+1 redundancy. It runs true online double conversion on an IGBT 3-level topology, up to 97% AC-AC, with a 100 kAIC option. A self-load-test mode runs burn-in from 20 to 100% load for 1 to 600 minutes with no external load bank, saving rental, cabling and labour. Mitsubishi backs the efficiency with a written performance guarantee and cites a 99.9995% sustained load-carrying figure from its installed base.
Source: Mitsubishi Electric, 9900D product page. Figures are Mitsubishi's published specifications.
Batteries and battery cabinets for the Mitsubishi Electric 9900D
Battery strings and cabinets depend on the configuration and runtime. For a replacement string in a Mitsubishi cabinet, see batteries for three-phase UPS cabinets.
Mitsubishi Electric 9900D service in Canada
We service the Mitsubishi Electric 9900D across Canada: preventive maintenance, battery replacement and emergency repair, including units the manufacturer no longer supports. We are a Canadian UPS service and supply provider, working on three-phase systems since 2012.
- Phone: 1 (438) 881-3363
- Email: info@threephaseups.ca
- Coverage: across Canada, in English and French
Planned visits and emergency calls are arranged through on-site service for the Mitsubishi Electric 9900D.
Sizing, redundancy and custom builds
We engineer the solution: load and growth analysis, redundancy (N, N+1, 2N), runtime and battery sizing, paralleling and switchgear, and custom configurations where the standard catalogue doesn't fit. Because we supply every major brand, the 9900D is one option we weigh on its merits, not the only answer.
Common questions
What is the Mitsubishi Electric 9900D?
The Mitsubishi Electric 9900D is a high-density three-phase UPS for large data centres rated 1,200 to 2,000 kVA at 480 V.
Is the Mitsubishi Electric 9900D discontinued?
No. Mitsubishi Electric lists the 9900D as current.
Who services the Mitsubishi Electric 9900D in Canada?
A Canadian UPS service and supply provider, in business since 2012, services the Mitsubishi Electric 9900D across Canada: preventive maintenance, battery replacement and emergency repair, including discontinued units. Call 1 (438) 881-3363 or email info@threephaseups.ca.
Request a quote: Mitsubishi 9900D
Tell us the application and we reply within 4 business hours with the sizing, the right system, the installation and a written quote. Three-phase installs usually need a licensed electrician, so let us know if you have one.
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.