Portable EMS, 50 A
Progressive Industries EMS-PT50X 50 Amp Portable RV EMS Surge Protector
The 50 A, 120/240 V version of the same electrical management system: both lines monitored independently, five-mode surge protection, and the same power-cutting response to voltage, polarity, ground, neutral and frequency faults.
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Best for
50 A RVs with two air conditioners, where a dropped leg or a low leg is the common campground problem
Specifications
| Service | 50 A, 120/240 V (12,000 W) |
|---|---|
| Surge protection | 5-mode (L1-N, L2-N, N-G, L1-L2, L-G); 3,580 J; 88,000 A; response < 1 ns |
| Low voltage | Shuts off below 104 V held for 6 s on either line (E 4 line 1, E 6 line 2) |
| High voltage | Shuts off above 132 V after 3 s; above 140 V after 1 s; above 156 V within 60 ms (E 3 line 1, E 5 line 2) |
| Wiring faults | Reverse polarity (E 1), open ground (E 2) and open neutral: power is never applied; accidental 240 V on a 120 V line: instant shutdown |
| Frequency | Shuts off below 51 Hz (E 8) or above 69 Hz (E 7) |
| Reconnect delay | 2 min 16 s (136 s) after a fault clears; 6 s start-up check |
| Display | Scrolls L1 and L2 voltage and current, frequency, error code and previous error code |
| Weather | Weather resistant (not submersible); use upright |
| Security | Built-in locking bracket for a cable lock |
| Warranty | Limited Lifetime (Progressive Industries) |
Specifications as published by Progressive Industries. Confirm against the current spec sheet before buying — manufacturers revise models without renaming them.
What's good
- Each 120 V leg has its own voltage, current and error codes, so a pedestal with one weak leg — the classic 50 A site fault — is caught and named
- Five surge modes including line-to-line, which a 30 A unit never needs and a 240 V service does
- Same conservative cut-offs and 136-second compressor delay as the 30 A unit
- Full protection on a 30 A or 20 A site through an adapter — the manual says so, with power limited to the lower rating
What's not
- Twice the joules of the PT30X, but a 50 A cord set and unit is heavier to carry and harder to park on a crowded pedestal
- Same floating-neutral generator behaviour: open ground, no power, until the generator is bonded
- No dimensions, weight or IP rating published on Navico's site
Our verdict
If the coach is 50 A, buy the 50 A EMS rather than running a 30 A unit on a dogbone — the line-to-line surge mode and the per-leg monitoring are the point. Weak or dropped legs show up on the display before you plug the RV in, which is the cheapest troubleshooting an RV park will ever give you.
Compare with the alternatives
- Progressive Industries EMS-PT30X — any 30 a rv that moves between campgrounds — the one unit to own if you buy only one
- Hughes Autoformers Power Watchdog Gen I – 30 Amp Surge Protector with Emergency Power Off – Portable (PWD30-EPO) — 30 a owners who want the pedestal readings on a phone inside the rv, and a surge module they can replace instead of the whole unit
- Southwire Surge Guard 34950 — 50A Portable Surge Guard with Enhancement, O/U, LCD, 50A 240V — 50 a rigs whose owners want a plain-english lcd readout and a lock ring on the cord, with a 30 a sibling (34930) for the smaller coach