DPDT Relay's question.

Xan2

Xan2

Well-Known Member
Hey guys,

I would like inputs on what timer to use with DPDT 120v relays.
I have 4 relays wired in parallel to a simple 15amp timer. I tought the coils where not drawing that much power until i saw the timer flipping in the dark room.
I saw a very huge spark trough the white timer casing wich has scared me a bit so i left the timer unplugged for now.

I would like some inputs about the relay's, can anyone confirm that the coils is drawing enough power to ignite a kind spark or is my timer bad?
I have other simple 15amp timers i am going to try tonight, but any inputs would be appreciated. Should those relays run on a heavy duty timer like T-104?


Anoyone?

(Sorry my english is bad, i know.)

Thanks.
 
SnapsProvolone

SnapsProvolone

Well-Known Member
Xan2 said:
Hey guys,

I would like inputs on what timer to use with DPDT 120v relays.
I have 4 relays wired in parallel to a simple 15amp timer. I tought the coils where not drawing that much power until i saw the timer flipping in the dark room.
I saw a very huge spark trough the white timer casing wich has scared me a bit so i left the timer unplugged for now.

I would like some inputs about the relay's, can anyone confirm that the coils is drawing enough power to ignite a kind spark or is my timer bad?
I have other simple 15amp timers i am going to try tonight, but any inputs would be appreciated. Should those relays run on a heavy duty timer like T-104?


Anoyone?

(Sorry my english is bad, i know.)

Thanks.
Click to expand...
Your contactors should be wired to a timer rated with enough ampacity to handle the sum of the amperage drawn by all contactor. On a 120 volt coil it should be miliamps.
The metal housing that I hope you have your contactors in should have the chassis grounded.
Switch contacts spark/arc but as long as used within their rated FLA (full load amperage) you are fine. Too much and contacts will often weld stuck or just melt down all together.
 
A

astroastro

Active Member
Snaps is right- the arcing is occurring across the switch contacts- not the coils. This occurs when the relay is turned off- there is current flowing in the circuit- when the switch contacts suddenly open (the relay is turned off) the current still wants to flow and will continue to flow across this arc until the gap between the switch contacts is too wide and the arc is extinguished. This occurs mostly with inductive loads like fan motors and perhaps core/ coil style HID ballasts. If you know something about electronics and can solder you can look at placing a resistive-capacitive 'snubber' across the relay switch contacts which will help reduce this arc and save your relay switch contacts from destroying themselves.
 
SnapsProvolone

SnapsProvolone

Well-Known Member
astroastro said:
Snaps is right- the arcing is occurring across the switch contacts- not the coils. This occurs when the relay is turned off- there is current flowing in the circuit- when the switch contacts suddenly open (the relay is turned off) the current still wants to flow and will continue to flow across this arc until the gap between the switch contacts is too wide and the arc is extinguished. This occurs mostly with inductive loads like fan motors and perhaps core/ coil style HID ballasts. If you know something about electronics and can solder you can look at placing a resistive-capacitive 'snubber' across the relay switch contacts which will help reduce this arc and save your relay switch contacts from destroying themselves.
Click to expand...
His arcing was, I believe, in the timer contacts not the dpdt contactors.
 
Xan2

Xan2

Well-Known Member
Thanks for the replys, i have replaced the timer and i don't see any arc or spark anymore.

And yes the arc was in the timer and not at the relays.

Thanks for your time guys.
 
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