TDEN timer on ATS

[SK092170]

Hello

Is a TDEN (Time Delay Emergency to Normal) timer on an ATS, an on-delay timer or an off-delay timer?

Thanks
SK092170

 

[ATSman]

Typically it is an on-delay timer (time delay on pickup.)
What is the manufacturer and model# of the ATS?

 

[SK092170]

Its an very old Asco 930 with a mechanical clock timer made by ITC/EPG.

 

[SK092170]

Coil to the timer is energized while the ATS is on normal source.

 

[ATSman]

Yes that's an oldie, built in the 60's early 70's.
And that should be the return timer. It starts timing once normal power returns then transfers the ATS after time out and stays energized till the next power failure.

 

[SK092170]

Yes that's an oldie, built in the 60's early 70's.
And that should be the return timer. It starts timing once normal power returns then transfers the ATS after time out and stays energized till the next power failure.

I think from looking at the schematic its also inline with the test switch which opens the circuit and simulates an outage. If its energized on normal source, would that be an off delay timer, or am I thinking about this in the wrong way?

 

[ATSman]

Can you send a clear pic of the schematic?
I have a dwg of a 935 : ASCO HS245-021-2 which should be similar to the 930 and shows TR2 as the TDEN.

 

[SK092170]

Can you send a clear pic of the schematic?
I have a dwg of a 935 : ASCO HS245-021-2 which should be similar to the 930 and shows TR2 as the TDEN.

 

[SK092170]

Will do. I will send it later this morning.

 

[SK092170]

Can you send a clear pic of the schematic?
I have a dwg of a 935 : ASCO HS245-021-2 which should be similar to the 930 and shows TR2 as the TDEN.

 

[SK092170]

I have been trying to attach a photo of the schematic with no success.

 

[ATSman]

Do you have it in a pdf file you can attach? If not just attach the jpg pic file.
If you tried that and it will not attach then it may be too large (megs)
try to lower the resolution of the file to kb's

 

[SK092170]

Here it is.

 

[ATSman]

Thanks for the file.
This dwg shows the following:
TDES - Acc 1A delay on dropout, engine start (RC circuit delays dropout of SE relay)
TDEN - Acc 3A delay on pickup, retransfer to normal, starts timing when 3 phase sensing contacts 1V, 2V, 3V close
TDEC - Acc 3D delay on pickup engine cooldown delay

 

[SK092170]

Thank you for your help on this!

 

[ATSman]

You're welcome!