The MTL4021 enables an on/off device in a hazardous area to be controlled by a volt-free contact or logic signal in the safe area. It can drive loads such as solenoids, alarms, LEDs and other low power devices that are certified as intrinsically safe or are classified as non-energy storing simple apparatus. By connecting a second safearea switch or logic signal, the output can be disabled to enable, for example, a safety system to override a control signal. Earth fault detection can be provided by connecting an MTL4220 earth leakage detector to terminal 6.

Power requirement, Vs

- - 100mA at 24V dc

- - 120mA at 20V dc

- - 75mA at 35V dc

Power dissipation within unit

- - 1.3W with typical solenoid valve, output on

- - 1.9W worst case

Isolation

- - 250V ac between safe- and hazardous-area circuits.