Rain Bird MDC2 - Troubleshooting Guide for the Decoder System

Troubleshooting, continued
90
Controller is
defective.
Controller display ON?
Start 50 Hz mode.
Check line voltage.
Is reading 33-40 VAC?
Check valve activation.
Is Inrush OK?
Next valve
Is decoder address OK?
Defective
solenoid
Defective
decoder
Correct address.
Next decoder
YES
NO
Bad
splice
Is switch ON?
Turn on switch.
One field cable?
Take
next cable.
Is current
in GND?
Is current >20 mA?
Not possible
to trace.
Use Clamp Ampmeter to
locate problem.
Connect both wires
to the same terminal
and trace leak.
Connect
one cable
at a time.
Is current OK?
YES
NO
Problem is in field.
Does the line current (50 Hz)
match decoders?
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
YES
NO
Disconnect lines
and measure again.
Is reading OK?
Problem
is in field.
One field cable?
Controller
is defective.
Use Clamp
Ampmeter to
trace short.
Connect one
cable at a time.
Is voltage OK?
YES
NO
YES
NO
Check next
cable.
Use Clamp
Ampmeter to
trace short.
YES
NO
Is supply
voltage OK?
Check fuses and
Mains switch.
YES
NO
Troubleshooting Guide for the Decoder System
Troubleshooting Guide for the Decoder System