The Phagwara frozen store is emptied and shut down for four weeks each summer for cleaning and maintenance. These are the rules for bringing the rooms back down to temperature afterwards.
Check that the floor heating has been running throughout the shutdown and that its current reading is normal. Check the doors close and seal, and the strip curtains are hung.
The floors at Phagwara are old and well dried, so the rooms are brought down without a hold at +2 C. The controller is set to cool at no more than 5 C per hour until the room reaches -22 C. A pulldown from ambient usually takes a little under two days.
Write the room temperature on the sheet every two hours. If the gradient on the sheet is steeper than the setting, stop the plant and phone the regional engineer.
The room holds its set point for 24 hours with the doors shut before the first pallet is put away. The shift lead signs the sheet to say it has.
The refrigeration contractor's duty engineer, on the number on the plant room door, for any alarm during the start-up. The site manager is told when each room has reached its set point, so that customers can be given a date for receipts.