Reversing contactor hot

[Mlmill]

Ok. Thabk you. Now we are getting somewhere. Anything else I need to do to fix this install? Without criticism...

[Mlmill]

Thanks sergio. To keep from getting contactor hot when not using go fast button, Should i install diode instead? Install across larger studs? Across smaller studs also? Any recommendation on what types so i can order??

[teecro]

Originally Posted by Mlmill

Thanks sergio. To keep from getting contactor hot when not using go fast button, Should i install diode instead? Install across larger studs? Across smaller studs also? Any recommendation on what types so i can order??

Diodes never go across the big ends, only across the small terminals and only with the banded end toward the hot wire. Their function is to absorb voltage inrush which shortens the life of small contacts...

[Sergio]

You don't need anything accross the big posts, and that solenoid itself would not cause the reversing contactor to get hot.

Where were the cables from the "go fast" connected, to the motor or reversing contactor?

After you install the contactor, if it gets hot again, take a picture and show where exactly it was so hot.

[tag50]

I thought diodes were used to avoid solenoid drop-out due to relative voltage drop and the resistors were used to avoid in-rush spikes to the controller caps.

Any clarification would be appreciated.


.

[teecro]

Originally Posted by tag50

I thought diodes were used to avoid solenoid drop-out due to relative voltage drop and the resistors were used to avoid in-rush spikes to the controller caps.

Any clarification would be appreciated.


.

Actually a flyback diode helps minimize the arc created when a switch is broken or opened so my use of the word inrush is not quite right but the end result is the same as it helps prevent damage to the small contacts in the switch cause if not by a spike but by a dip...

A pre-charge resistor is a device that slowly charges the capacitors inside a electronic speed controller before it is powered up. Without this resistor, closing the contactor would generate a large amount of inrush current causing the contacts to arc. This arcing can permanently weld the contacts in the "on" position. The inrush current from not pre-charging can also cause the contact tips to get pitted resulting in a poor connection and diminish vehicle performance. Oddly no resister is called for in the Curtis 1268 controller I use on my cart.

[Mlmill]

Originally Posted by Sergio

Where were the cables from the "go fast" connected, to the motor or reversing contactor?

Connected at S1 and S2 on motor

[Mlmill]

Originally Posted by Sergio

After you install the contactor, if it gets hot again, take a picture and show where exactly it was so hot.

Gets hot on brass bar with "X" marked on it. Keep in mind, it is getting hot just running cart without using the button.

[Mlmill]

Originally Posted by Mlmill

Gets hot on brass bar with "X" marked on it. Keep in mind, it is getting hot just running cart without using the button.

Forgot to mention it only gets hot on brass bar (and cylindrial black plastic piece behind bar). All the wires and lugs on contactor are cool.

[Sergio]

Because of the massive current carrying capacity of the Normally Open Contacts, those contactors have pretty strong coils.

The Continuous duty models have a 20w coil and the Intermittent duty ones 60w.

I never measured the temperature of the operating coil, so I don't know how quick the temperature will climb while in operation.

You can certainly measure the coil resistance to make sure it is within tolerances.

Disconnect the wires from the small tabs of the coil and measure the resistance, the specs calls for approximately 140Ω.