Conformal-coated power module for harsh environments
The Siemens 6AG1138-4CB11-2AB0 is a SIPLUS ET 200S PM-E power module that brings the functionality of the standard 6ES7138-4CB11-0AB0 into a wider temperature range and with conformal coating. It accepts dual supply ranges — 24-48 V DC and 24-230 V AC — and includes diagnostics plus an integrated fuse. The conformal coating protects the PCB against condensation, corrosive gases, and salt spray, making this module a fit for environments where standard ET 200S gear would fail early.
Temperature range and environmental tolerance
Rated for -25 °C to +60 °C ambient, this module covers the extended temperature band required in unheated enclosures, cold stores, or outdoor-adjacent cabinets. It also meets Level GX group A/B for corrosive gases (excluding trichlorethylene), Level LC3 for salt spray, and Level LB3 for oil — per ANSI/ISA-71.04 and EN 60721-3-3 class 3C4 limits. The standard 6ES7138-4CB11-0AB0 lacks this coating and the full environmental qualification.
The 5 W maximum power loss is low enough that no additional ventilation slot is needed in most enclosures, but at 60 °C ambient the cumulative heat from a fully populated rack should be checked against the cabinet's thermal budget.