Raymarine linear drive + NAC3 won’t engage

[hanslamitraille]

Hello all,

My AC42N computer failed during our Atlantic crossing. “Clutch overload” reported by the Zeus2. After investigation I found out burnt components in the AC42. In this day and age, no fixing. So I had to replace it with a new NAC3.
During dock commissioning the clutch wouldn’t engage and I found out the clutch coil on the Raymarine T2S-24V linear drive was fried.
Changed the coil... by a used one but functional.

At this stage I thought everything would be easy : I had tested the clutch by sending 12V to it and the motor by sending 24V. All good.

But... the clutch doesn’t engage during the rudder test, part of the commissioning process. The motor of the linear drive does turn during the test, but it is pointless as the clutch isn’t engaged.
I looked for for voltage coming out of the “drive engage” connections on the computer board with the clutch cables CONNECTED : nothing. I then REMOVED the clutch cables and there I get about 17V when starting the test!

So here is the question and the mystery if any of you smarter than me have a clue :
Why doesn’t the NAC3 sends voltage to the clutch coil when it is hooked up to it?

Thanks for reading about my problem that I am trying to solve at anchor while under lockdown

[Lency]

Hello Hans,

It's been a while since you posted this, but as we are having pretty much the same issue with the same equipment, I was curious as to whether you were able to find the cause of the clutch not engaging?

Cheers,
Lex