ZJ400D contactor trouble

[Jusp]

Hi,

I am converting my 30ft sailboat from inboard diesel to electric, and bought the 5 kW BLDC with controller, plus a ZJ400D contactor.
This contactor is giving me some trouble. I know that this is not directly a Goldenmotor product, but I cannot really find good information on this item, and hope that someone on this forum can answer my question.

I understand e.g. from the following website that the allowed coil voltage is 6-220V. So I applied 12V from a regular car battery to the coil, but the contactor refuses to switch.
Measuring the coil with a multimeter, it seemed fine. What coil voltate does it expect?

Thanks,

Juul


https://www.aliexpress.com/item/ZJ400D-NO-normally-open-style-Coil-Voltage-24V-400A-DC-Contactor-for-motor-forklift-electromobile-grab/1594796191.html

[Bikemad]

Hi Juul andto the forum.

The website you linked to shows different versions of the contactor are available for the following voltage options:

12V
24V
36V
48V
60V
72V

And the contacts are rated for 6-80V, so I'm not sure what the "Coil voltage of contact circuit (V)  6V-220V" actually relates to. 

The coil voltage should be marked on the body of the contactor, similar to these:



The above contactor has a coil rated for 12VDC but the contacts are rated for 400A @ 80VDC.
The contactors shown below just have the coil voltage marked, but the contacts are presumably capable of switching 400A @ the marked voltage:







Hopefully your contactor will be clearly marked too.



Alan
 

[Jusp]

Yep, that explains it. I have a 48 V one, but had assumed that that referred to the rated voltage over the open switch.
I wired up my 48V battery bank and heard it solidly connecting. Works all the way down to 30V, but I want to switch it with 12V, so will order another contactor

Thanks,

Juul

[Bikemad]

A cheaper alternative to buying a new contactor would be to use a simple 12V relay to switch the 48V battery voltage to the contactor coil. 



As the contactor's coil only consumes 8-12 Watts, the contacts of the 12V relay would only have to carry ~0.25A.

Alan