What it is – three isolated relay outputs in an ET 200SP slice
The 6ES7132-6HC50-0BU0 is a three-channel relay output module for Siemens ET 200SP. Each channel is a changeover contact isolated from the others, so you can switch separate loads without a common return. The module itself is 20 mm wide, fits on a BU type U0 base unit, and accepts either 24 V DC or 230 V AC supply, though the relay coils run on the DC rail.
Current ratings and derating – what drives the real limit
At 40 °C ambient the module can handle 15 A total across the three relays, but watch per-channel limits: above 40 °C the total drops to 12 A, and each channel is capped at 4 A. That per-channel ceiling often bites when you try to parallel outputs for a larger load. The relay outputs switch lamp loads up to 2 Hz, so fine for solenoids and contactors but not for fast strobes.
Field installation notes
Max cable length is 1 000 m shielded, 200 m unshielded – fine for most drops within a panel or local junction box. Automatic encoding means the base unit reads the module type and maps I/O addresses without manual DIP switches. Diagnostics include a channel status LED per output and a combined DIAG LED for module health. Redundancy capability is built in for critical loops.