Short answer: match your RV's plug (30A TT-30 or 50A 14-50), and prefer an EMS (electrical management system) that cuts power on low or high voltage and wiring faults, not just surge spikes.
| If you need… | Look for |
|---|---|
| Occasional campground stays | Portable surge protector with wiring-fault lights |
| Old or busy campgrounds | EMS with low/high-voltage shutoff and delay on restore |
| Full-time RVers | Hardwired EMS (theft-proof, always on) |
| 50A rig at a 30A pedestal | Adapter plus a protector rated for the plug you connect to |
| Generator use | Check how the protector handles generators (some need a bonded neutral) |
A basic surge protector absorbs spikes (rated in joules) and shows wiring faults. An EMS also disconnects on low voltage (which can damage AC compressors), high voltage, open neutral and reverse polarity, then reconnects after a delay. Check pedestal voltage before plugging in; low voltage is common on busy summer afternoons.
Safety: These are general estimates, not a design. Follow your equipment manufacturer's instructions and local electrical code, and consult a qualified electrician for anything connected to shore power, a house, or high-current batteries.
A surge protector handles spikes; an EMS also cuts power on low/high voltage and wiring faults. Low voltage is a common cause of AC damage, so many RVers choose an EMS.
Match the plug you connect to the pedestal. A 50A rig plugged into a 30A pedestal through an adapter needs protection rated for that connection.
Portable is easy to install and move; hardwired can't be stolen and protects every time. Both work if they are rated for your service.
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