"Sun Dragon" wrote in message
...
Hi,

I have a Robertson/Simrad AP45 pilot currently using mechanical relays to
control the steering pumps. Pumps are 240 VAC not sure of the HP or
current,
probably 2 or 5 HP motors.

Is there any reason I can't replace the noisy troublesome mechanical
relays
with a solid state relay such as a Teledyne like this:

http://www.mouser.com/catalog/629/1447.pdf

Thanks,

Capt. Vin


Sure. Works great. Just be sure you get some rated for the starting
current spike of your motor(s?). It seems to me like the control voltage
output from the basic AP45 pilot house control was 12 volts DC, and if I
remember correctly (long, long time ago) the voltage went "high" to start
the motor controller. (lots of pilots would "sink" a motor controller's port
or starboard control voltage, so beware!)
Good practice when dealing with the autopilot's input control voltage
to these high voltage solid state relays is to use an opto-isolator device
to reduce the possibility of a voltage spike frying the autopilot. Expensive
like you can't believe.

Old Chief Lynn