Got fed up with the Solid State Relay approach! grabbed a 10k resistor and a Power MOSFET, soldered the MOSFET casing to a strip of brass, put thermal compound on the back of the brass strip and bolted it to the SSR heat sink. Connected it up to the RUMBA, Power Supply and heated bed, powered on and it works like a charm. 19.2 amp draw gives a voltage drop of 0.17volts across the MOSFET, with no appreciable heating! Back to work on more designs!