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Magnum Digitrip 1150

The Magnum Digitrip line of trip units consists of the model 1150 that conforms to UL standards, and model 1150i that conforms to IEC standards. Appendix B in the 1150 trip unit instructional leaflet includes a troubleshooting guide.

Protection settings options (set in the PGM SET -> CURRENT menu):

  • LSI - Long delay, Short Delay, Instantaneous
  • LSIG - Long delay, Short Delay, Instantaneous, Ground Fault Trip
  • LSIA - Long delay, Short Delay, Instantaneous, Ground Fault Alarm
  • Instantaneous trip can be disabled

External control power is not required to operate the basic overcurrent protection functions; the trip unit operates through current sensors mounted in the breaker. When the breaker trips, an LED on the trip unit will indicate the cause of trip. The battery behind the trip unit door is used to power these cause of trip LEDs. External control power IS required for all other features (connected to pins A14-A15). The display will not be on unless external control power is supplied.


  • Arc Flash Reduction Maintenance Mode (ARMS) - can reduce arc flash incident energy that is generated on a fault condition.
  • INCOM communications:
    • The Power Xpert Gateway can be used to translate INCOM to an Ethernet connection (Modbus TCP, BACnet/IP, SNMP v.1/v.3).
    • Opening and closing the breaker via communications requires a shunt trip and spring release and additional wiring.
  • Current metering:
    • Starts at 0.02 per unit of the rating plug value.
    • The tolerance is +/-1% of the rating plug value for phase and neutral, and +/-2% of the rating plug value for ground.
  • PT module for voltage and power metering:
    • Connected to the top terminals by default (option to connect to the bottom terminals).
    • The tolerance for voltage metering is +/-6.9V.
    • The tolerance for power metering is +/-2% of the rating plug value multiplied by 6.9V.
    • Some metering screens may need to be enabled before they show up in the metering menu: PGM SET -> DISPLAY.
  • Voltage protection can be programmed in the PGM SET -> VOLTAGE menu.
    • Once voltage settings are enabled, you can turn on specific voltage protections (ex: undervoltage) and set the parameters. Make sure to set the level and then the next screen will be the time delay.
    • If any voltage protections are turned on, the breaker will trip per those settings. No extra wiring is required.
    • If there is a mechanical trip flag and OTS contacts, those will change state if the breaker trips due to the voltage protection settings.
    • Control power is required for the voltage protections to be active. If control power is lost, the breaker will not trip on any of the programmed voltage protections.

The Power/Relay Module:

  • Control power is connected to A14-A15.
    • This is designated as ATR_VOLT and ATR_V_COM on the wiring diagram. ATR = Automatic Trip Relay. For DC voltage, A14 (ATR_VOLT) is the positive, and A15 (ATR_V_COM) is the negative.
  • Four voltage ratings: 120 Vac, 230 Vac, 24–48 Vdc, and 125 Vdc (100–140 Vdc operating range).
    • +/-10% except for 125 Vdc which has an operating range of 100-140 Vdc.
  • 10 VA power consumption.
  • Without auxiliary power, the display will not be active, and there will be no communications or voltage protections.
    • Protection features will be active once the load current reaches approximately 30% single-phase or 10% three-phase of the In rating.
      • The programmed settings are remembered even though you can't see them without control power.
    • ARMS can be enabled using a remote switch with logic level contacts wired to pins B7-A12 even without trip unit control power.
      • Without auxiliary power, the display cannot indicate that ARMS is enabled, and the relay contacts will NOT change state (there will be no indication that ARMS is enabled).
  • ​​​​​​​The green status LED at the bottom right of the trip unit blinks approximately once per second to indicate normal operations when the trip unit is powered from either load current or the power supply module.

Time/current curves are available on the Magnum website.

How to change the settings

Factory default settings

Test kits

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