MTL5526 Switch Operated Relay
The MTL5526 enables two separate IS circuits in a hazardous area to be relay-contact controlled by two on-off switches or logic signals in a safe area. Applications include the calibration of strain-gauge bridges: changing the polarity (and thereby the tone) of an IS sounder; the testing of I 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 remain safe if connected together.
See also common specification Number of channels Two, fully floating Location of control circuit Safe area Input/output characteristics Contact/Logic mode (Inputs suitable for switch contacts, an opencollector transistor or logic drive) Relay energised < 1V applied Relay deenergised > 2V applied (35V max.) Loop powered mode Relay energised if >20V Relay de-energised if <17V Power supply failure protection Relays deenergised if supply fails Response time 25ms nominal Contacts (suitable for connection to IS circuits) 1pole changeover per channel Contact rating 250V dc, limited 30V dc for IS applications, 2A (reactive loads must be suppressed) Contact life expectancy x 107 operations at maximum IS load Relay drive (see switch setting table) Switch selection of loop powered or contact/logic control for both channels. Further switch selects "1in2out" mode LED indicators Yellow: one provided for each channel, ON when relay is energised Green: one provided for power indication Power requirement, 35V dc Power dissipation within unit 1.1W maximum at 24V Safety description (each channel) Non-energystoring apparatus: relay contacts may be connected to any IS circuit without further consideration