Penn A421 Series, Installation Manual

Page: 10 / 14

Control adjustment is now restricted to changing only
the OFF value, which shifts the On and OFF control band
within the restricted adjustment range defined by HtS and
LtS (Figure 9).
Note: To completely restrict and lockout all user
adjustment on the control, set the HtS value equal to
the On or OFF value and the LtS value equal to OFF or
On value. Then the (On to OFF) control band is equal
to the restricted adjustment range (LtS to HtS) and
the OFF value cannot be adjusted in the restricted
mode.
Adjusting the control in Restricted mode
In this task you adjust the OFF value and shift the On and
OFF control band within the restricted adjustment range,
when the control is in the restricted adjustment mode.
1. In the Main screen, press MENU to go to the
restricted adjustment mode menu and display the
OFF parameter code screen (Figure 11).
2. To go to the OFF value screen, press MENU .
3. In the OFF value screen, press Down or Up to change
the OFF value within the restricted adjustment range.
4. To save the selected OFF value and return to the OFF
code screen, press MENU .
5. To return to the Main screen, press Down and Up
simultaneously.
Figure 11: Adjusting temperature in the Restricted menu
Troubleshooting
A421 Series Controls display fault codes on the LCD as
described in Table 4.
Table 4: Fault Codes Defined
Fault code Definition System status Solution
SF flashing
alternately
with OP
Open
temperature
sensor or
sensor wiring
Output
functions
according to
the selected SF
mode
See Troubleshooting
procedure . Cycle
power to reset the
control.
SF flashing
alternately
with SH
Shorted
temperature
sensor or
sensor wiring
Output
functions
according to
the selected SF
mode
See Troubleshooting
procedure . Cycle
power to reset the
control.
EE Program
failure
Output is off To reset the control,
press MENU . If
problems persist,
replace the control.
Troubleshooting procedure
1. Check for proper voltage to the A421 Control.
a. To remove the cover, loosen the two captive cover
screws.
b. Use an AC voltmeter to check the voltage between
the COM and 120V or 240V terminals on line-
voltage models. See Figure 4.
Note:
The voltage must be between:
- 102 VAC and 132 VAC for 120 VAC
applications
- 177 VAC and 264 VAC for 208/240 VAC
applications
c. If the voltage reading is not within the required
range, check the power source and input power
wires for problems.
2. Check for proper sensor operation.
a. Disconnect all power sources to control.
b. Using an accurate thermometer, take a
temperature reading at the sensor location.
c. Disconnect the sensor from the control.
d. Using an ohmmeter, measure the resistance
across the two sensor leads while the sensor is at
the temperature taken in Step 2b.
e. Consult Figure 12 to verify that the measured
temperature and resistance conform to
established temperature and resistance values.
f. If the measured values conform to the values in
Figure 12, proceed to Step 3.
g. If the sensor’s measured resistance value is
substantially different from the expected value
for that temperature, check the sensor wiring. If
sensor wiring is correct, replace the sensor.
A421 Series Electronic Temperature Controls with Cycle Timer Installation Guide 10