Hand – Off – Auto

When Carrying out Energy Assessments, I will always ensure I put some of my attention into the Motor Control Centre (MCC). This is where most of the plant for the heating, ventilation and cooling will be controlled from. You need to be mindful that there could be more than one MCC panels within the building. The first thing I do when I see an MCC Panel within the plant room is to scan the control switches twice. The first time checking to see if all switches are facing the same way (Good practice amongst control panel manufacturers is to maintain convention and ensure there is a standard way of indicating). My second scan reviews the switches that are not facing the same way. This tells me if there are any control issues to record.

This means that this pump will be running 24hours a day and not running as programmed to run.

Therefore, this is costing money.

This could be increasing the buildings kWh Consumption by 15 – 20%

Whilst carrying out the Assessment:

1. View the MCC Panel and scan the Switches and identify which switches are in ‘Hand’ you would expect them all to be in ‘Auto’
2. Take a picture for evidence, I have seen the client quickly put back into ‘Auto’ we are not trying to catch anyone out but understand how to improve the properties efficiency.
3. Train staff while you are in front of the MCC to do this and advise them to either do daily of weekly to ensure plant is not being tampered with.
4. Identify the plant this is controlling and try and calculate the kWh for this equipment to be hand.

Why could the switch be placed in ‘Hand’?

The are many reasons why these switches could be put into ‘Hand’:

1. Maintenance team have put the plant into ‘Hand’ and forgotten to put back.
2. Control Issues with the Building Management System (BMS) and plant is put into hand or it will not run.
3. The BMS is Faulty
4. The BMS time zones are incorrect.
5. The BMS time clock is incorrect and the time zones are not working correctly.
6. Someone wanted to put this ‘on’ out of hours for a function or for an event, but they have not been put back.

What to do if the control switch is in ‘Hand’

If the control switch is in ‘Hand’ these are the actions to take:

1. Report to the maintenance manager who may be with you.
2. With the permission on the maintenance team switch the control switch to Auto.
3. If the plant stays running check the time-zones and monitor
4. If the plant does not work, possible call a BMS specialist to review the control system.