Problem

This is the electric drive of the bypassvalve in the piping of the combustion air supply to the boiler.It suddenly gave alarm: the deviation between real position of the valve and the setpoint had become too high.
We have two of these: each of them is situated in a duct that has the dimensions of a deliveryvan...
So: normally the output of the unit is regulated by a central dispatch centre, about 80 miles away but now we have to do it all by hand because this thing roughly spoken regulates the amount of air to the boiler and is very important...
The drive still works electric, only the position of the valve we cannot see in the control room. So it's not so bad as a few years ago when the electric motor broke down, at that time we had to move the valve by a chain block.