Raymarine type 1 linear drive -power cable sizing

[skyflyer]

Busy fitting a below deck a/p and , surprise surprise, the power cable on the type 1 linear drive isn't long enough to reach the control unit (partly because i decline to locate the box of electronics in the relatively wet area of the steering gear/ aft lazaretto!)

So a quick check in the manual says for runs of 0 to 7m, use 2 sq mm cable

Great - except the cable attached to the drive is only 1.5mm diameter, so about 1.75 sq mm

The manual also says that the power run calculation should add the power to the control unit and the run to the drive, which may in my case total over 7m (by the time you faff around routing the cables out of sight and away from all the everyday electrical items that spell instant doom to a network signal - fluorescent lights being one!). In this case the manual recommends 4sq mm!

The drive will draw 15A max and there is a separate clutch control circuit which apparently can draw 2A, and then the whole SeatalkNG backbone power supply also comes from the same source which sort of explains the 20A fuse.

Best stick with 2mm? Or simply match the size of the existing wiring on the ram?

 

[prv]

Great - except the cable attached to the drive is only 1.5mm diameter, so about 1.75 sq mm

If it's short, they don't have to worry about volt drop. If you're making a long one, you do, hence the larger cable needed.

The manual also says that the power run calculation should add the power to the control unit and the run to the drive,

Makes sense - the voltage is dropping over that whole length, not just the part of it after the control box.

away from all the everyday electrical items that spell instant doom to a network signal - fluorescent lights being one!)

But this isn't a network signal, it's just power.

In this case the manual recommends 4sq mm!

The wiring I inherited was a pair of 2.5mm² in parallel. When I replaced it (along with all the other wiring) I believe I used 6. The thing can push half a ton when working hard, it needs to be properly fed to achieve that.

Pete