Siemens PTB — Power Termination Board, catalogue number 500-033390, the AC mains termination for PSC-12 and PSX-12 power modules in Desigo Modular and Cerberus PRO Modular panels.
It filters incoming AC mains and distributes it to the PSC-12 charger and the optional PSX-12 extender. It mounts on threaded studs in a CAB enclosure, and each supply must sit directly above the board feeding it, joined by a 12-inch keyed cable.
- TB1 takes AC mains, hot on TB1-1 and neutral on TB1-2; TB2 feeds the next PTB
- P4 and P5 each feed one PSC-12 or PSX-12, so one board serves two supplies
- Carries an AC-line filter and 5 A AC-line breaker protection
- Mains rating per supply: 3.5 A at 120 VAC, 2.5 A at 220 VAC, 2.0 A at 240 VAC
- One PTB fits a CAB-1; one or two fit a CAB-2BB, CAB-2RB, CAB-3BB or CAB-3RB
- Ordered on its own it comes with four number 10 hex nuts and nothing else
Count supplies rather than trust a rule of thumb: Siemens data sheets 7322 and 8322 give two different thresholds for a second board, so work from the two connections each provides. PSX-12M is a different part and pairs with a PSFA.
