A Restore-Lite 40kVA is the published 40kVA temporary restoration cart. SNC lists it as P80100: 40kVA, 120/240V, 200A breaker, 220 lb, floating-tap transformer, meter-head or pedestal cord set.
The PowerBack 50kVA is the unit built for the same multi-home job at a higher current class: 50kVA, 400A recommended service, 400A breaker, 208A continuous per hot leg, 105 C transformer shunt trip, Cam-Lok secondary landing.
These five reasons are amperage and protection, not branding.
The current math that matters
| — | Restore-Lite 40kVA (P80100) | PowerBack 50kVA |
|---|---|---|
| Transformer rating | 40kVA | 50kVA |
| Current at 240V (kVA ÷ 240) | about 167A | about 208A |
| Published breaker | 200A | 400A |
| Published continuous current | not stated as a per-leg continuous figure | 208A continuous per hot leg |
| Thermal trip | not published as a winding-temperature shunt trip | 105 C sensor trips the breaker |
| Extra protection | optional CT, trips if 10A for 5 seconds on that CT | optional GFI / 8A imbalance |
| Landing | meter head or pedestal cord | Cam-Lok on the utility secondary |
| Weight | 220 lb | 290 lb |
40kVA at 240V is about 167A. A 200A breaker can stay closed above the transformer rating. That gap is the safety issue.
Reason 1: The breaker is larger than the transformer
On Restore-Lite 40kVA, the published machine is a 40kVA transformer behind a 200A breaker.
40,000 VA ÷ 240V ≈ 167A.
If load sits between about 167A and 200A, the breaker has not reached its trip region and the transformer is already above nameplate. A parked unit on a multi-home pedestal can live in that band all afternoon.
PowerBack 50kVA publishes the continuous number that matches the kVA: 208A continuous per hot leg (50,000 ÷ 240). The 400A breaker is the fault and landing device for a 400A-class secondary. The transformer is not asked to hide behind a breaker that is larger than its continuous rating with no thermal backup.
Reason 2: Dual trip closes the band a breaker cannot see
Overcurrent protection only sees amps. Winding heat is a different failure.
Restore-Lite 40kVA published protection is the 200A breaker. The optional CT trips the breaker if that CT sees 10A for 5 seconds. That CT is installed on a conductor between the meter base and the ground rod. It is a ground-current / leakage style trip. It is not a winding-temperature trip.
PowerBack 50kVA has two paths:
- 400A breaker for high current
- Temperature sensor in the transformer that shunt-trips at 105 C
If the pedestal load is “legal” on the breaker and the winding is climbing, dual trip is the path that opens. That is the safer spec for a unit that may sit for days, including on a house with solar export.
Reason 3: 400A-class service vs 200A-class restore
A Restore-Lite 40kVA is a 200A-breaker device. That matches a large single service or a small combined load.
A multi-home pedestal or a multi-meter cabinet is often a 400A-class landing. Several 150A or 200A services share one secondary. Combined current is not one house.
PowerBack 50kVA is specified as 400A multi-home, with a 400A breaker and 208A continuous per hot leg. Using a 200A-breaker cart on a 400A secondary asks the small machine to stand in for the bank.
| Ticket | Current class that fits |
|---|---|
| One 200A house | 200A-class cart (20kVA / Restore-Lite 40kVA territory) |
| Two or three homes on one pedestal | above one 200A restore |
| Multi-meter cabinet on one incoming secondary | 400A-class PowerBack 50kVA |
| Unknown diversity at the pedestal | 400A-class PowerBack 50kVA |
Reason 4: Continuous per-leg current is published
PowerBack 50kVA states 208A continuous per hot leg. That number is the 50kVA rating written as current. Operations can check load against a published continuous value.
Restore-Lite 40kVA states the unit restores load current on an open hot “up to the unit’s designated current rating,” and on an open neutral “up to the current rating in neutral current.” The designated published device rating next to that language is the 200A breaker, not a separate continuous-per-leg figure aligned to 40kVA (about 167A).
A safer spec names the continuous current the transformer can carry, then names the breaker, then names the thermal trip. PowerBack 50kVA publishes all three. Restore-Lite 40kVA publishes the breaker and an optional 10A / 5s CT.
Reason 5: Secondary landing keeps restoration current off a single meter socket
Restore-Lite 40kVA is installed between the customer meter base and the service, with a meter head or a pedestal cord set. Restoration current goes through that adapter path.
PowerBack 50kVA lands three conductors on the utility secondary through a Cam-Lok kit:
400A breaker → 10 ft unit lead → Cam-Lok → 5 ft whip → utility secondary
The breaker stays off to connect or remove. Grounding is required. Voltage is confirmed at a customer meter (120V hot-to-neutral, 240V hot-to-hot) before the crew leaves.
For a multi-home pedestal, putting 400A-class restoration through one meter adapter is the wrong current path. Landing on the secondary is the safer current path.
What this does not claim
The Restore-Lite 40kVA is lighter (220 lb vs 290 lb). It is a real 40kVA published product. It is not a 400A-class dual-trip machine.
Safer here means: breaker and transformer ratings line up, winding temperature can trip the breaker, and high current lands on the secondary instead of one socket.
FAQ
What is the Restore-Lite 40kVA current rating?
Published device: 40kVA, 200A breaker. 40kVA at 240V is about 167A.
What is the PowerBack 50kVA current rating?
50kVA, 400A recommended service, 400A breaker, 208A continuous per hot leg.
Why is a 200A breaker on a 40kVA transformer a problem?
The breaker can remain closed above the transformer’s 240V nameplate current. Dual trip is how you cover that band.
Is the Restore-Lite optional CT the same as dual trip?
No. The optional CT trips at 10A for 5 seconds on that CT circuit. Dual trip is breaker plus transformer winding temperature.
When is Restore-Lite 40kVA still the right size?
One large service that fits a 200A restore and a meter-head landing. Not a 400A multi-home pedestal.
Product Callout
Bridgeport Magnetics PowerBack 50kVA
Safer Restore-Lite 40kVA alternative for multi-home work: 50kVA, 400A class, 208A continuous per hot leg, 105 C dual trip, Cam-Lok secondary landing.
Phone: (203) 954-0050
Email: [email protected]
bridgeportmagnetics.com/powerback
