DOL Starters Automatic Change Over

[Dimspark]

Guys
I have 2 DOL starters which share the same supply for 2 toilet extract fans I have a selector switch wired up and and a set of auxilliary
normally closed contacts on each of the DOL starters to prevent both fans running at the same time. If possible could some one point me please in the direction of a diagram to allow me to wire the fans for automatic changeover in the event of the duty fan tripping out on overload as there is no nanatural ventillation in the toilet core .
I have 2 trip lamps to indicate which fan has tripped and I have wired up the DOL starters for automatic changeover via the overload on the dol starters connections 96 and 97 my problem is the way I have wired it is that if I set fan 1 as duty, the trip lamp on fan 2 is on even though fan 2 has not tripped I know why the lamp is on but I dont have the intelligence to solve the issue that is why I am asking for help from the forum members
Thanks Dimspark

 

[Lucien Nunes]

It's hard to say what's wrong without seeing your circuit. As I understand it, the indicators are meant to show a tripped condition but instead are just showing that a fan is not running. Therefore I assume they are being controlled by the contactors not the overload relays? You mention terminal 97 - do you have both N/C (95-96) and N/O (97-98) on the overload relay? If so this is fixable. The control feed can go to both overload relays 95 & 97 first. Each 98 controls its trip indicator independently of everything else. Then each 96 feeds one pole of the DP C/O duty selector, which energises the contactor directly when set to duty but via the opposite contactor's N/C interlock contact when set to standby.

Tomorrow I could draw this if unclear. Are there any remote controls / start & stop buttons?

 

[Dimspark]

It's hard to say what's wrong without seeing your circuit. As I understand it, the indicators are meant to show a tripped condition but instead are just showing that a fan is not running. Therefore I assume they are being controlled by the contactors not the overload relays? You mention terminal 97 - do you have both N/C (95-96) and N/O (97-98) on the overload relay? If so this is fixable. The control feed can go to both overload relays 95 & 97 first. Each 98 controls its trip indicator independently of everything else. Then each 96 feeds one pole of the DP C/O duty selector, which energises the contactor directly when set to duty but via the opposite contactor's N/C interlock contact when set to standby.

Tomorrow I could draw this if unclear. Are there any remote controls / start & stop buttons?

 

[Dimspark]

Thanks Lucien a diagram would be most helpful in the meantime I am going to try and draw out how I have wired the contactors there are no remote buttons
Thanks Dimspark