Product Overview
The Single Phase 208/240V Line Voltage Monitor and Surge Protector offers easy installation along with pre-wired protection against voltage spikes and lightning strikes. It is a combinations of several protective layers all included in a single unit for protection of your HVAC system. The Sentry-SF-30A Sentry SmartFuse combination device includes an ICM517A-LITE single phase surge protector and an ICM492DX, a single phase voltage monitor. Overcurrent protection is achieved with field selectable fuses from 5 - 30A to match your equipment needs (fuses are not included). Additionally an onboard disconnect breaker is also included. All this is packaged in a NEMA 4X outdoor rated (≈ IP66), UL94-5VA flame rating, UV rated enclosed box. The Sentry-SF-30A is designed in a modular fashion with easily replaceable individual components.
The ICM517A-LITE, a Single Phase Wet Location Surge Protector will protect your mini split against voltage spikes as well as lightning power surges. It is fully encased in a NEMA Type 4x waterproof enclosure. This surge protector is for use with mini splits, air conditioners, refrigeration systems and other electronics and appliances. It is installed on your electrical panel. Suitable for use on a circuit capable of delivering not more than 10,000 rms symmetrical amps, 240 volts max, when protected by a circuit breaker rated 15 to 60 amps maximum and 120 volts minimum.
The ICM492DX, a Single Phase Digital Line Voltage Monitor (LVM) offers top-tier protection against voltage spikes and dips. Featuring a bank of five surge arrestors, it provides added safety for your valuable electronics, especially mini split systems. The newly designed ICM492DX includes all of the features of the ICM492D including tactile push buttons, backlit display screen for low light conditions and LED lights load energized, control, set up and fault. Additionally, the ICM492DX has an increased fault memory from 5 events to 50 events on the ICM492DX. The Voltage Setpoint has been moved from a percentage target voltage to a numerical value for more precise settings.- Minimum Circuit Ampacity (MCA): 24A
- Maximum Over Current Protection (MOCP): 30A
- You may install up to a 30A fuse or breaker
- You may NOT install a 45A or 50A breaker
- For most HVAC installations, the installer does not need an electrical license to install the Sentry SmartFuse
- Pre-wired for 240 VAC
- Modular design with field-replaceable parts
- Programmable voltage monitor with backlit display + 50-fault memory
- Protects from over/under voltage and rapid short cycling
- 40A contactor fully disconnects service
- 30A internal breaker for easy power on/off
- Superior TFMOV surge protection for reliable safety
- Built to handle major surge impacts
- Proudly innovated and designed in the USA
- NEMA 4X outdoor rated (≈ IP66), UL94-5VA flame rating, UV rated
- UL listed (ICM517A-LITE E347279, ICM492D E53944), UL 508A; meets NEC 440.22(A) 2026
- Limited lifetime product warranty up to a 3-year $25,000 connected equipment warranty
- Inputs:
- Line Voltage: 240VAC
- Frequency: 50/60 Hz
- Breaker: 30A at 240VAC
- Outputs:
- Contactor: 60A FLA, 208/240VAC
- Surge Protection:
- Maximum Surge Current: 60,000 amps
- Short Circuit Current Rating (SCCR): 5kA
- Green LED Light: Protected when lit
- Protection Modes: L-L, L-G
- Voltage Monitor (Default Settings):
- Voltage set point: 240VAC
- Delay on Break (ASC): 15 seconds
- Over/under voltage: 5%
- Delay on Fault: 2 seconds
- Fuses (Field Supplied; not included):
- RK1 & RK5 type fuses 5-30A
- Mechanical:
- Case dimensions: 14”L x 9.75”W x 6”H
- Unit Weight: 6.9lbs.
Tech Specs
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