The MTL4504 enables a safe–area load to be controlled, through a relay, by a proximity detector or switch located in a hazardous area. Line faults are signalled through a separate relay and indicated on the top of the module. MTBF information for the LFD relay is available from Eaton to allow the failure rate for the LFD relay to be calculated when used in the critical path with the output relay for safety critical applications. Switches are provided to select phase reversal and to enable the line fault detection.

Technical Data

Number of channels

One

Location of switch

Zone 0, IIC, T6 hazardous area

Div.1, Group A, hazardous location

Location of proximity detector

Zone 0, IIC, T4–6 hazardous area, if suitably certified

Div.1, Group A, hazardous location

Line fault detection (LFD) (when selected)

User-selectable via switches on the side of the unit. Line faults are indicated by an LED. Line fault relay is de-energised and channel output relay de-energised if input line-fault detected.

Open-circuit alarm on if Iin < 50µA

Open-circuit alarm off if Iin > 250µA

Short-circuit alarm on if Rin < 100Ω

Short-circuit alarm off if Rin > 360Ω

Note: Resistors must be fitted when using the LFD facility with a contact input

500Ω to 1kΩ in series with switch

20kΩ to 25kΩ in parallel with switch

LED indicators

Green: power indication

Yellow: channel status, on when output energised

Red: LFD indication, on when line fault detected

SIL capable

These models have been assessed for use in IEC 61508 functional safety applications.

SIL2 capable for a single device (HFT=0)

SIL3 capable for multiple devices in safety redundant configurations (HFT=1)

MTL4504