Water flow and dew point sensors have been installed on the outlet and inlet cooling water manifolds respectively.

Outputs indicating good water flow and ambient temperature above the dew point are connected via an interlock box (constructed by Peter Black)
to the USB-controlled ac mains relay which provides remote control of ac mains power to the AIDA FEE64 PSUs.

The interlock box (see attachment 1) has 

1x 24V dc power input (ac mains transformer)
4x sensor inputs (1x dew point, 1x flow and 2x unused, dummy cable inputs)
4x outputs (1x connected to USB-controlled ac mains relay, 3x unused)

When all sensor inputs are OK, 4x yellow LEDs (corresponding to each of the 4x sensor inputs) are illuminated and visible through the transparent
lid of the interlock box - see attachment 2
The USB-controlled ac mains relay yellow 'water' LED is illuminated if interlock is OK - see attachment 3


B+B Sensor Dew Point Controller - attachments 4 & 5
 red led (top right) indicates sensor above dew point

Micronics U1000 Mk II Clamp On Ultrasonic Flow Meter - attachments 6-9

 Setup as follows
  Pipe ID: 44mm
  Reading: Flow
  Units: litres
  Flow Units: l/min
  Pipe Material: M/Steel
  Set Separation: C 3

 All other settings default

 Not possible to attach sensor assembly to electronics module for some reason but cabling is attached and unit appears to
 work OK. Typical flow c. 75 l/min with signal strength c. 75% - see video attachment 10

Sunday 6 April
 FEE64 power OFF
 Valve OFF outflow
  Flow rate reported by Micronics U1000 Mk II decreases fro c. 75 l/min to 0 l/min over a period of c. 10-15s
  USB-controlled ac mains relay - yellow 'water' LED off
 Valve ON outflow
  Flow rate recovers c. 10-15s

Monday 7 April
 FEE64 power ON
 Valve OFF outflow
  Flow rate reported by Micronics U1000 Mk II decreases fro c. 75 l/min to 0 l/min over a period of c. 10-15s
  AIDA PSUs OFF as flow -> 0
 Valve ON outflow
  USB-controlled ac mains relay - yellow 'water' LED ON
  AIDA PSUs remain OFF
  Rly16 browser tab continues to display 'power ON' and OK status - attachment 11
   but unable switch ALL off
  To recover - clsoe Rly16 browser tab, reboot nnrpi1 and restart MIDAS server


 Valve ON outflow