MTL 2000 Intrinsically Safe Isolators

The MTL2000 series intrinsically safe isolators are DIN-rail or surface mounted devices available as 1-, 2-, or 3-switch configurations or as an IS relay for bringing back status or command signals from switches or proximity detectors and an IS relay to switch hazardous-area loads.

The MTL2210B enables two 500VA safe-area loads to be controlled in separate circuits simultaneously by one light-duty on/off switch in a hazardous area. Alternatively, it can be arranged to latch for pushbutton stop/start control of an electric motor, the relay then being energized by brief closure of one switch contact and de-energized by the brief opening of another. The stop switch overrides the start switch, even if the start circuit is closed, making sure that the motor can be turned off under all conditions. In this application, the second pair of changeover output contacts enables the status of the motor to be fed to a computer or data logger

The MTL2211 enables two 500VA safe-area loads to be controlled independently through two relays by two light-duty on/off switches in a hazardous area. The two input circuits are independently fully floating and are unaffected by each other. Each relay is provided with two sets of changeover contacts, which are connected in parallel within the unit for maximum reliability. Applications include the operation of medium-powered electrical equipment such as alarms, lights, and small electrical motors, or contactors for controlling higher powered equipment.

The MTL2213 enables three 100VA safe-area loads to be controlled independently by three light-duty on/off switches or certified proximity detectors in a hazardous area. Switches and proximity detectors may be mixed. The three input circuits are interconnected but fully floating. For proximity-detector and some switch applications, a phase-reverse link allows alarm conditions to be signaled for either state of the sensors. ‘Alarm' means relays de-energized with their on/off contacts open, and all three circuits have to operate in the same fashion. This compact low-cost unit is suitable for a wide variety of applications.

The MTL2215 enables either one or two separate IS circuits in a hazardous area to be relay-contact controlled by a single on/off switch or logic signal in a safe area. Applications include the calibration of strain-gauge bridges, changing the tone of an IS sounder, the testing of IS fire alarms, and the transfer of safe-area signals into an annunciator with IS input terminals not segregated from each other. The output-relay contacts are certified as ‘non-energy storing' apparatus, and can be connected to any IS circuit without further certification, provided that separate IS circuits are such that they would still remain safe if connected together.