Rotax100uk
19-07-2007, 08:46 PM
I have been on a project of building a blast chiller, only a small two pallet one but we have installed 6 fan motors into the side if the coldroom panels to force the chilled air into the pallets harder, anyway the fan motors are 240v (single phase) with start capacitor (4uf) i have taken a single phase off of the outdoor unit which is 3 phase to run the fan motors, the supply comes from the outdoor unit to the top of the blast chiller on the roof and to a contactor so that the thermomax controller turns them on and off.
Right heres the problem when you try to run all 6 fans off the one phase they cause the fans to run backwards, (in other words they blow back into the ductwork)
So with this i then tried to find out how many could run the right way until they changed direction anyway two fans is all you can have running off the one phase before they change direction,
So again trying something else i brought all 3 phases from the out door unit to the contactor and decided to wire 2 fans per phase which from what i have already found out should be fine and they will all run the right way, BUT still they dont run the right way at all when there is six wired,
Any help would be great thanks.
Right heres the problem when you try to run all 6 fans off the one phase they cause the fans to run backwards, (in other words they blow back into the ductwork)
So with this i then tried to find out how many could run the right way until they changed direction anyway two fans is all you can have running off the one phase before they change direction,
So again trying something else i brought all 3 phases from the out door unit to the contactor and decided to wire 2 fans per phase which from what i have already found out should be fine and they will all run the right way, BUT still they dont run the right way at all when there is six wired,
Any help would be great thanks.