top of page

IS4-L: Latching Relay with Intrinsically Safe Inputs

• Latching Logic


• Pump Down or Pump Up


• 4 Channels


• Shorted Input Sensing


• Open Input Sensing


• Contact or Probe Inputs


• Output and Input LED



Four Channel Latching Relay 

Supply voltage must be applied to the IS4-L relay during operation. The latching logic is set up for a pump down operation. (Pump up is available too.) When IS input #1 closes its LED changes and #1 output contact closes. When IS input #2 closes, output contact #2 closes, latches in and starts the first pump. When IS inputs #3 and #4 close, Output contacts #3 and #4 latch closed, respectively. All output contacts remain closed, even if their inputs open, until input #1 opens, and all output contacts open, indicating that the system has pumped down. LED indicators will be: Red - When the IS input is open or high Green - When both the IS input & output contact are closed Amber - Latch Logic - IS input open & Output closed Flashes - During transition delay A green LED indicates when supply voltage has been applied to the IS4-L.




Supply Voltage: 24, 120 & 240VAC ±10%

Power: 2VA

Inputs: Switch Closure or Probe (Conductivity)

Input Sensitivity: 3K - 1.5MΩ

Pick-up & Drop-out Delays: 1 second

Max. Open Circuit Voltage: 5 volts AC

Max. Source Current: 0.1 milliamp AC

Output Rating @ 25°C:

     5 Amps or 100VA per contact

     10 Amps total

     250VAC maximum contact rating

     10,000,000 Mechanical Cycles



Mounting: Din Rail mount

Termination: Touch safe screw terminals, with lift mechanism,

     #12 AWG max.

Weight: 10 Oz.


Ambient Temperatures

Operating: 0°C to 50°C

Storage: -40°C to 85°C


bottom of page