Hussmann Proto-Aire Installation Manual page 115

N/A, go to the Protocol™ configuration menu and access the Protocol Setup
submenu. Enter the DEFR Setup program the control with the correct
number of defrost circuits. Repeat this step to verify that the circuit is
activated.
Step B7 Verifying the defrost circuit configuration. Check the number of defrosts
per day, the defrost length and defrost start times to ensure proper
configuration. Go to Step B9.
Step B8 Verifying the Defrost Output Assignments. Verify that the correct output(s)
have been assigned to the appropriate defrost circuit. Now that all
programming information has been verified, return to Step B3 to force the
defrost on.
Step B9 Verifying the Defrost Output Assignments. Verify that the correct output(s)
have been assigned to the appropriate defrost circuit. If the correct outputs
have been assigned, and the status reveals the circuit is in defrost, and check
the ribbon cable between the control board and defrost board. Try replacing
the ribbon cable with one from another Protocol™ to verify they cable is
good or bad. If the cable is good, replace the control board. The defrost
output drive chip has possibly been damaged. If the correct outputs have
not been assigned, enter the correct programming and repeat this step.
Step B10 Electrical Wiring Check. Use a digital voltmeter to verify where the circuit
is being broken. Power for defrost solenoids originates from the 'X1'
terminal block, passes through the fuse relay located on the defrost board,
and ends at the terminal block located in the power distribution block. If the
fuse on the defrost board has blown, try replacing it with another fuse and
repeat the voltage checks.
For electric defrosts, a minimum of two defrost outputs will be used for
defrost: one for the solenoid and one for the defrost heaters. The power for
the solenoid can be checked as described previously in this step. To verify
the defrost heater wiring go to Step B12.
Step B11 POWERLINK™ wiring. You may want to first familiarize yourself with
information on POWERLINK™ Operation as detailed in this manual.
Visually inspect that the circuit breaker handles of the POWERLINK™(S),
located on the bus bars within the control panel, are in the ON position. If
the handle is in the ON position, use a digital meter and check for voltage at
the terminals of the POWERLINK™ device and again at the terminal blocks
in the power distribution panel. If voltage is not present at these two points,
got to Step B13.
Step B12 POWERLINK™ Power Supply Check. Using a digital meter, inspect the
POWERLINK™ Power Supply, which provides power for the
POWERLINK™ device. Set your digital meter for DC voltage. There
should be 24 VDC across the terminals of the POWERLINK™ Power
Protocol™ Installation and
111
Service Manual