18-120

18-120

The Model 18-120 3-Phase Monitor provides essential protection for industrial equipment. It continuously monitors for phase loss, low voltage, and phase reversal, safeguarding motors and other critical systems from operational anomalies. The unit incorporates an automatic reset function, minimizing downtime without manual intervention. Adjustable trip delays, ranging from 1 to 30 seconds, allow for precise response timing to transient conditions. Furthermore, a configurable restart delay, from 1 to 300 seconds, ensures controlled system re-engagement after a fault. This precise control over operational parameters contributes to enhanced system reliability and longevity, reducing maintenance requirements and improving overall process stability.

The Model 18 continuously monitors 3-phase power lines for abnormal
conditions. When properly adjusted, the Model 18 monitor will detect
phase loss on a loaded motor even when regenerated voltage is present.
This device consists of a microcontroller with a voltage and phase-angle
sensing circuit, driving an electromechanical relay. When correct
voltage and phase rotation are applied, the internal relay will
energize. A fault condition will de-energize the relay. When the fault
is corrected, the monitor will automatically reset. An adjustable
restart delay prevents short cycling in compressor applications and an
adjustable trip delay prevents nuisance tripping during power
fluctuations. The Model 18 does not require a neutral connection and
can be used with Wye or Delta systems. Voltage ranges are sufficiently
wide to allow for proper adjustment to existing conditions. Both FAULT
and NORM condition indicators are provided to aid in adjustment and
system trouble-shooting. The Model 18 is UL Recognized in the U.S. and
Canada and is available with optional gold flashed silver contacts for
low current applications.

Out of stock

Specifications

DetectionPhase loss, low voltage, phase reversal
Reset TypeAutomatic reset
WarrantyFive year unconditional warranty
Nominal AC (phase to phase)120VAC
Adjustment range85-120VAC
Frequency60Hz
Power consumption1.4W
Transient protection2500VAC for 10ms
Repeat accuracy± 0.1% of set point (fixed conditions)
Trip delay1-30 sec.
Restart Delay1-300 sec.
Dead bandApproximately 2%
Output contactsSPDT 10 amps at 240VAC resistive
Expected relay life (Mechanical)10 million operations
Expected relay life (Electrical)100,000 operations at rated load
Operating temperature-20° to +131° F
Humidity tolerance0-97% w/o condensation
Terminal Torque3.5 in. lbs. maximum
Wire TypeStranded or solid 14-28 AWG, 1/terminal
Enclosure materialNORYL plastic
MountingDIN Rail or Surface Mount
Low Current OptionModels ordered with suffix '/SG' will have silver with gold flash contacts (SPDT 5 amps at 120VAC resistive)
Agency ApprovalUL Recognized (U.S. and Canada)
Usage EnvironmentFor use in a Pollution Degree 2 Environment
Dimension Tolerance± 0.06"

FAQs

What types of phase conditions does the 18-120 monitor detect?
The 18-120 3-Phase Monitor detects phase loss, low voltage, and phase reversal. It operates within an adjustment range of 85-120VAC for 120VAC nominal systems.
What are the adjustable delay ranges for the 18-120 monitor?
The 18-120 features an adjustable trip delay from 1 to 30 seconds and an adjustable restart delay from 1 to 300 seconds. These settings allow for tailored system response.
What are the specifications for the output contacts on the 18-120?
The 18-120 is equipped with SPDT 10 amp output contacts at 240VAC resistive. These contacts have an expected electrical relay life of 100,000 operations at rated load.