View Full Version : star delta

15-08-2014, 06:53 PM
Hi guys i have started working for new conpany that deals with alot more industrial tackle than im used to i have had to fit a 3ph condensor fan the old fan had six wires the new one apparently only needs 3 with 6 terminals i dont even know wjere to start as a colleague took it off and the new guy gotta go fix it any advice is greatly appreciated

install monkey
15-08-2014, 07:59 PM
look on the back of the electrics cover- modify the links for star- if its 3 phase dol , cant start a fan or motor in delta- too much start up current- either link all 3 together u2,v2,w2 and stick ur 3ph on u1 v1 w1 - check rotation is correct, if it buzzes its nuts off then its the other way- u1-u2 link v1-v2 link and w1-w2 link and ur 3phase goes on u1,v1,w1

15-08-2014, 08:07 PM

That link has information which can help you with star delta starting. My question is why are you changing to 3 wires now? What size motor is this? Take a picture of the motor terminals and the starting contactors and post them here if you need more real advise.

15-08-2014, 09:04 PM
Its a really really old r22 7.5hp prestcold unit the original fan had 6 wires and the new one has 6 terminals but there is no links for it and beimg honest i aint really done anything on star delta the company i used to work done commercial refrigeration but this is a more industrial company

install monkey
15-08-2014, 09:18 PM
can you see where the original 6 wires go to the original motor connections?- if so connect the same- or wait for monkeyspanners - dr prestcold! haha

15-08-2014, 09:44 PM
The connections off the old one were a1 a2 b1 b2 c1 c2 i couldbt even say the name of the motor because i really have no idea and the new motor is a remco with uvw u1 v1 w1 connections but the old motor had 6 tails hence wjy im really confised

15-08-2014, 10:02 PM
All 3 phase motors have 6 wires. 3 windings, each end of the windings equals 6 connections.
U1 U2 = winding 1
V1 V2 = winding 2
W1 W2 = winding 3
How to wire them either Star or Delta is best explained here https://docs.google.com/document/d/1nfqzsq9Sh3PTiXP6joFZE14VUnHZhdswi0Jh3ncViN8/edit?hl=en_US

15-08-2014, 10:06 PM
On the flex i had 6 red blue black grey white yellow 3 of thos are phases its the outher 3 that confusedme where do they go on the motor

16-08-2014, 03:40 PM
You'll only need one set of wires from the first or main contactor, disconnect the other three so no surprises, as for connection on motor, as install monkey suggests use diagram on new fan.

monkey spanners
16-08-2014, 06:44 PM
Usually with the really old Prestcold ones (ones with motor in a cradle and seperate blade) the phases go on the red,yellow,blue and you join the brown,black,white together to make the star point. There is also usually two purple or maybe grey wires that are the thermal overload for the fan that need wiring in to the control circuit with the pressure switches.

Possibly the new motor has its star point already made inside or like IM says you need to make it with brass links.
I've not fitted one of them size motors for 10+ years assuming its one of the 370/550 watt ones. If its the 120 watt ones where the condenser has more than one it sounds like you may have the wrong replacement one, but i am not overly familiar with Remco so could be wrong!

16-08-2014, 10:09 PM
You are dead right monkey spanners there were no brass links supllied with the motor so i connected them on the relevent terminals and the bolldy thing never ran not unless i use a wire link across the 3 terminals and disconnect the 3 wires as suggested

17-08-2014, 06:59 AM
Are these wires conected from the original star delta starter? If you are changing your starting method to direct on line starting which uses 3 wires only then u have to use a direct on line starter. If you managed to read through the manuals on the links given by myself and Frank it should be easy for you now. For a 7.5hp motor it is ideal to use star delta starting method. I still insist that you post pictures of the motor terminals and your starter if you need a quick resolution to your problem.

17-08-2014, 08:53 AM
There will be pictures if i ever go back to site all the help you guys have gave so far has been great