The Laumas MTL7766Pac is a 2-channel passive Zener barrier for load cell/scale power supply circuits in ATEX and IECEx-certified hazardous areas. Each channel provides Uo = 12 V, Io = 157 mA, Po = 471 mW; channels can be paralleled for Uo = 12 V, Io = 314 mA, Po = 942 mW. DIN/Omega rail mounting with extractable screw terminals.
The MTL7766Pac is a passive intrinsic safety Zener barrier designed to protect scale/load cell power circuits in hazardous locations – including gas (Zone 0,1,2), & dust (Zone 20,21,22), Class I, II, III Div 1. Zener barriers work by diverting fault voltages to ground through low-resistance Zener diodes and fuses, preventing sparks and overheating of the scale components in the hazardous area.
The MTL7766Pac specifically handles the excitation supply side of a scale circuit, delivering safe-area DC power through the barrier to load cells and junction boxes located in the hazardous zone. It is used in combination with the MTL7761ac signal barrier, which handles the millivolt signal from the load cell/scale back to the safe-area weight indicator or transmitter. Together, the two barriers provide a complete intrinsically safe load cell interface for weighing systems in oil and gas processing, chemical plants, grain silos, Original Equipment Manufacturer (OEM), and mining environments.
| Barrier Type | Passive Zener barrier, power supply |
|---|---|
| Channels | 2 channels, analog signal |
| Certifications | ATEX, IECEx, FM |
| Maximum Output (Uo) | 12 V |
| Maximum Current (Io) | 157 mA |
| Maximum Power (Po) | 471 mW |
| Operating Temperature | -20°C to +60°C (-4°F to +140°F) |
| Mounting | Omega / DIN rail |
| Dimensions | 4.1 x 3.4 x 0.5 in (105 x 87 x 12.6 mm) |