Most motorhomes that use these early model Intellitec ECC system have a shore power capacity of 30 amps. SHEDing is a way of preventing electrical loads inside the motorhome from exceeding 30 amps and tripping circuit breakers.
SHED is when the ECC detects a possible overload and shuts down one of the compressors to reduce the load. It SHEDs the load. The ECC monitors the 30 amp circuit, when it starts an A/C unit and compressor, if it sees that the current is exceeding about 28 amps, it’ll shut the compressor off again, this is called SHEDing.
How Waiter ECC performs SHEDing:
Before commanding a compressor to start, Waiters ECC does what we call a Pre-SHED check to determine if starting the compressor might cause an overload. If it appears like it would, then starting is delayed until the amps being drawn is reduced enough to allow the compressor to be started.
If the compressor is started, if the amps exceed about 28 at any time, the compressor is shut off, SHEDed. When this happens, the compressor cannot be restarted until a hard start delay (2 minutes) has elapsed. This “hard start delay” allows the head pressure in the compressor to bleed down, making it easier to start the compressor..
What is Pre-SHED? – In the CONFIG screen, the approximate BTU ratings of each A/C unit is selected. Waiters ECC uses this to estimate how much current the compressor will draw when its started. Before starting the compressor, it adds the estimated amps to the amps the motor-home is currently drawing, if this exceeds about 28 amps, the compressor will not be started.
SHED is displayed on the operators touch screen as a red square in the upper right corner of the small window.
Pre-SHED is displayed as an alternating rec/green square.