ATSE for Hospital Power Continuity
Hospital power continuity is a load-class problem before it is a product problem. Group 0 and Group 1 medical locations, life safety systems and non-essential services have different tolerance to interruption, and the changeover arrangement should follow that grouping rather than a single site-wide rule.
- 01
MOTE Electric ATSE equipment for hospital projects is tested to IEC 60947-6-1 and available from 100A to 3200A in PC class and CC class.
- 02
Transfer time is adjustable per board, so life safety and medical sub-boards can be set differently on the same site.
- 03
Hospital changeover assemblies are supplied as coordinated switchgear where the project requires a single-build responsibility.
Which loads need changeover
Group the boards by the loads they serve, then read the tolerated interruption from the most sensitive load on that board.
| Load | Tolerated Interruption | Notes |
|---|---|---|
| Operating theatres and recovery | ≤ 0.5 s (medical IT / UPS supported) | Normally supported by medical IT or UPS, with ATSE on the upstream supply |
| ICU and critical care | ≤ 0.5 s – 15 s | Essential sockets supported; ATSE provides source changeover |
| Life safety — fire pumps, smoke control | Meets local life safety rule (commonly ≤ 15 s generator supply) | Dedicated essential board with 3P or 4P changeover |
| Medical equipment and imaging | Equipment dependent; often UPS buffered | Confirm manufacturer ride-through before fixing the delay |
| Lifts and bed lifts | ≤ 15 s | Motor load — check restart current after transfer |
| Non-essential and general services | Not time critical | Deferred transfer to protect generator capacity |
Typical ATSE configuration
Ratings, poles, class and delay settings commonly used on each board type.
| Board | Current Rating | Poles | Class | Transfer Time Setting |
|---|---|---|---|---|
| Essential main board | 1000A – 1600A | 4P | PC / CC | 1 s – 10 s |
| Medical sub-board | 400A – 800A | 4P | CC | 0.8 s – 5 s |
| Life safety board | 400A – 800A | 3P / 4P | PC / CC | 0.8 s – 5 s |
| Small equipment sub-board | 100A – 320A | 3P / 4P | CC | 0.5 s – 3 s |
What to settle before the order
Start from load class, not from the switchboard
Map each board to the load class it serves, then set the maximum acceptable interruption for the most sensitive load on that board. The ATSE delay settings follow from that number.
Coordinate generator start with bridging delay
The changeover should absorb generator start and stabilisation. Set a bridging delay long enough for the generator to accept load, and verify it against the load's ride-through.
Confirm neutral treatment for 4-pole switching
Where the changeover switches neutral, the earthing system and downstream residual current protection must be reviewed together with the 4-pole decision.
Products used on these boards
Questions on this application
What transfer time do hospital loads actually need?
It depends on the load class. Medical locations such as theatres are usually UPS or medical IT supported and tolerate a very short interruption, while lifts and general essential services commonly accept up to about 15 s for generator supply.
Should a hospital essential board use a 4-pole ATSE?
Four-pole switching is used where neutral switching is required for the earthing system or downstream residual current coordination; it is a design decision, not a default.
Is a PC class or CC class device used for hospital boards?
Medical and equipment sub-boards commonly use CC class so the device itself includes short-circuit breaking, while main essential boards may use PC class with upstream protection in the coordination study.
Does MOTE Electric supply a complete changeover assembly for hospitals?
Yes. Where the project calls for a single-build responsibility, the ATSE is supplied inside a low voltage changeover assembly with bypass, control and signalling.
Continue with another sector
Ask for a configuration review
Send the board schedule and the interruption each board tolerates. We will return a class, rating and delay proposal.