SpongeBob's Power Management System

[davidbrady]

All the magic happens in what Vantare calls the Bay Interface Module (BIM). The BIM is probably the most complex portion of the conversion's electrics. It allows remote control of the 120VAC motorized circuit breakers in the Main Distribution Panel (breaker box). A momentary push button switch panel upstairs in the living quarters lets the user select which loads are on or off. Pushing a switch sends a signal to the BIM instructing the BIM to change the state of the circuit breaker.

To accomplish this Vantare used a product developed by Square D called Powerlink AS. The unfortunate part is that Powerlink AS has been superseded by Powerlink G3 which will soon be superseded by G4... Sigh! (This only proves to me that it's wise to be able to debug and support the AS version rather than chase newer products that seem to have very short lifetimes). Fortunately, there are many NOS parts available for the AS; furthermore, I'm told that the system is very reliable but having a couple spare 15, 20, and 30A motorized circuit breakers on hand seems prudent.

The breaker box houses the Powerlink AS Programmable Interface Module (PIM) which is essentially a programmable controller. The PIM uses a low voltage bus to control each motorized circuit breaker. It does this by receiving Square D Sy/Max commands over an RS232 or RS485 bus. (I'm sure you recall the age old and venerable RS232 and RS485 protocols). Sy/Max is Square D's communication protocol.

The Bay Interface Module receives a signal from the upstairs switch panel, it decodes the signal and translates it into a Sy/Max command and sends it out it's RS485 interface to the Powerlink Programmable Interface Module (PIM). The PIM then signals the motorized circuit breakers to make a change in state. The Bay Interface Module also drives the LEDs at the user switch panel: Green - circuit energized; Red - circuit deenergized; Blinking - load automatically pruned by the Automatic Power Management System.

The Automatic Power Management System is simplicity onto itself. It looks for available shore or generator power. If neither is available it sends a "phase-loss" signal to the PIM and the PIM uses it's internally pre-programmed configuration to prune off pre-configured loads preventing inverter breaker tripping. As far as I can tell, all configuration and circuit breaker state is stored in the PIM and it's fully programmable meaning that I can choose which loads get pruned.

So, the system uses two discrete components from Square-D, the Powerlink AS PIM and the 15/20/30 amp motorized circuit breakers. Vantare then homebuilt their control circuitry implementing Square D's Sy/Max protocol to drive the PIM and to drive the user switch panel LEDs and interface with the switch panel momentary buttons. The Power Management System is gotten virtually for free from the PIM. The BIM contains circa 2000 componentry. I really think that if I should have any issue with the Vantare portion, much of it can be replaced by an Arduino or similar single board computer, which would be a lot of fun!

Here's a pic of the Powerlink PIM (A) in the pic and how it bolts cleanly into the panel box: