To allow the control of the heating elements used without the Hot Liquor Tank and the Copper vessel, I constructed a small box to house the higher voltage electrics required for this. Housing it all in one self contained box is a lot safer and may help with any electric interference problems with the other electronic equipment.Each heating element is driven through a Solid State Relay house in the box, A Solid State Relay (SSR) is an an easy to use method of driving a high voltage device from a low level voltage input. All the necessary electronics and electrics are already self contained within the SSR, Even the necessary zero voltage switching circuitry to allow the device to turn on or off smoothly at any time during an AC cycle is already included.
Each SSR is powered through a rail mounted Residual Circuit Breaker (RCD) to ensure a safety cutout should any problems occur with the cabling or heating element.
I also installed a neon for each Relay so I could see exactly when each heating element is driven. And drilled a small hole to also make visible the Solid State Relay LED so I could see when both Solid State Relay Input and Outputs were active.
The inputs to the Solid State Relay are then connected through a small opto isolator board to outputs on the Pokeys57e controller board. The opto isolator board is to give a separation between any problems on the Solid State Relay and the Pokeys57e board. It’s a lot cheaper and easier to replace the opto isolator board than to replace the Pokeys57e board if any problem occured.
After the internal components were mounted I then installed a nice label on the front of the box and small perspex windows so I could see the status of the Circuit Breakers and also the SSR Led’s.
I hope you’ll agree that the finished product looks rather nice.