Fault codes / Progressive EMS / L1 LOW / L2 LOW

Surge Guard: L1 low / L2 low

What it means: Below 102V on that leg.

What to check

Voltage drop or a weak park. Meter no-load and loaded.

Learn the system

• Shore power: 30A vs 50A
• Breakers, GFCIs and the EMS
• The lost neutral (50A danger)
• Transfer switches and generator power

Practice it on a service call

• Half the coach is dead
• Bathroom outlets are dead
• Lights surge and the microwave died

Guided diagnosis

• 120v System
• 50a Power Problems

Other Progressive EMS codes

• Progressive EMS code E-0 Normal, power passing
• Progressive EMS code E-1 Reverse polarity: hot and neutral swapped
• Progressive EMS code E-2 Open ground
• Progressive EMS code E-3 Line 1 high voltage, above 132V
• Progressive EMS code E-4 Line 1 low voltage, below 104V
• Progressive EMS code E-5 Line 2 high voltage, above 132V (50A only)
• Progressive EMS code E-6 Line 2 low voltage, below 104V (50A only)
• Progressive EMS code E-7 Frequency high, above 69 Hz
• Progressive EMS code E-8 Frequency low, below 51 Hz
• Progressive EMS code E-10 Surge module used up
• Progressive EMS: Display dark, no power Open neutral (no code for it)
• Surge Guard: Open ground No ground at the pedestal or in the cord
• Surge Guard: Reverse polarity L1 or L2 landed on neutral or ground
• Surge Guard: L1 high / L2 high Above 136V on that leg
• Surge Guard: L1 amps / neutrip Current over 110% on a leg, or neutral over 130% (50A)
• Surge Guard: Recept overheat Plug or receptacle running hot
• Surge Guard: GND high Voltage on the ground conductor
• Surge Guard: Open neutral Neutral lost on the coach side
• Surge Guard: Replace surge Surge protection expended

Full field guide: Progressive Industries EMS and Surge Guard

Codes come from the maker manuals and public service sheets. Your model's own chart always wins, and LP and 120 volt work belongs to a qualified technician.