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77
Table 93 — Time Clock Configuration
TROUBLESHOOTING
The scrolling marquee display shows the actual operating
conditions of the unit while it is running. If there are alarms or
there have been alarms, they will be displayed in either the cur-
rent alarm list or the history alarm list. The Service Test mode
allows proper operation of the compressors, fans, and other
components to be checked while the unit is not operating.
Complete Unit Stoppage —
There are several condi-
tions that can cause the unit not to provide heating or cooling.
If an alarm is active which causes the unit to shut down,
diagnose the problem using the information provided in
the Alarms and Alerts section on page 93, but also check for
the following:
• Cooling and heating loads are satisfied.
• Programmed schedule.
• General power failure.
• Tripped control circuit transformers circuit breakers.
• Tripped compressor circuit breakers.
• Unit is turned off through the CCN network.
Single Circuit Stoppage —
If a single circuit stops
incorrectly, there are several possible causes. The problem
should be investigated using information from the Alarms and
Alerts section on page 93.
Service Analysis —
Detailed service analysis can be
found in Tables 94-96 and in Fig. 14.
Restart Procedure —
Before attempting to restart the
machine, check the alarm list to determine the cause of the
shutdown. If the shutdown alarm for a particular circuit has
occurred, determine and correct the cause before allowing the
unit to run under its own control again. When there is problem,
the unit should be diagnosed in Service Test mode. The alarms
must be reset before the circuit can operate in either Normal
mode or Service Test mode.
Thermistor Troubleshooting —
The electronic con-
trol uses five 5K-thermistors for the saturated condensing
temperature on 48/50AJ,AK,AW,AY units (SCT.A and
SCT.B). See Tables 97 and 98 for temperature vs. resistance
data.
When replacing thermistors SCT.A and SCT.B, reuse the
original hardware. These thermistors must be clamped tightly
to the hairpins of the condenser.
The EDT, OAT, RAT, LAT, T55, T56, and T58 space tem-
perature sensors use 10K thermistors. Resistances at various
temperatures are listed in Tables 99 and 100.
THERMISTOR/TEMPERATURE SENSOR CHECK — A
high quality digital volt-ohmmeter is required to perform this
check.
1. Connect the digital voltmeter across the appropriate
thermistor terminals at the J8 terminal strip on the main
base board.
2. Using the voltage reading obtained, read the sensor tem-
perature from Tables 97-100.
3. To check thermistor accuracy, measure temperature at
probe location with an accurate thermocouple-type
temperature-measuring instrument. Insulate thermocou-
ple to avoid ambient temperatures from influencing
reading. Temperature measured by thermocouple and
temperature determined from thermistor voltage reading
should be close, 5° F (3° C) if care was taken in applying
thermocouple and taking readings.
If a more accurate check is required, unit must be shut down
and thermistor removed and checked at a known temperature
(freezing point or boiling point of water) using either voltage
drop measured across thermistor at the J8 terminal, or by deter-
mining the resistance with unit shut down and thermistor dis-
connected from J8. Compare the values determined with the
value read by the control in the Temperatures mode using the
scrolling marquee display.
ITEM
EXPANSION
RANGE
POINT
DEFAULT
TIME
TIME OF DAY
HH.MM
Hour and Minute
00:00
TIME
DATE
MONTH,DATE,DAY AND YEAR
MNTH
Month of Year
multi-text strings
MOY
DOM
Day of Month
0-31
DOM
DAY
Day of Week
multi-text strings
DOWDISP
YEAR
Year
e.g. 2003
YOCDISP
SCH.L
LOCAL TIME SCHEDULE
PER.1
PERIOD 1
PER.1
DAYS
DAY FLAGS FOR PERIOD 1
Period 1 only
PER.1
DAYS
MON
Monday in Period
YES/NO
PER1MON
Yes
PER.1
DAYS
TUE
Tuesday in Period
YES/NO
PER1TUE
Yes
PER.1
DAYS
WED
Wednesday in Period
YES/NO
PER1WED
Yes
PER.1
DAYS
THU
Thursday in Period
YES/NO
PER1THU
Yes
PER.1
DAYS
FRI
Friday in Period
YES/NO
PER1FRI
Yes
PER.1
DAYS
SAT
Saturday in Period
YES/NO
PER1SAT
Yes
PER.1
DAYS
SUN
Sunday in Period
YES/NO
PER1SUN
Yes
PER.1
DAYS
HOL
Holiday in Period
YES/NO
PER1HOL
Yes
PER.1
OCC
Occupied from
00:00
PER1_OCC
00:00
PER.1
UNC
Occupied to
00:00
PER1_UNC
24:00
Repeat for periods 2-8
HOL.L
LOCAL HOLIDAY SCHEDULES
HD.01
HOLIDAY SCHEDULE 01
HD.01
MON
Holiday Start Month
0-12
HOL_MON1
HD.01
DAY
Start Day
0-31
HOL_DAY1
HD.01
LEN
Duration (Days)
0-99
HOL_LEN1
Repeat for holidays 2-30
DAY.S
DAYLIGHT SAVINGS TIME
DS.ST
DAYLIGHT SAVINGS START
DS.ST
ST.MN
Month
1 - 12
STARTM
4
DS.ST
ST.WK
Week
1 - 5
STARTW
1
DS.ST
ST.DY
Day
1 - 7
STARTD
7
DS.ST
MIN.A
Minutes to Add
0 - 90
MINADD
60
DS.SP
DAYLIGHTS SAVINGS STOP
DS.SP
SP.MN
Month
1 - 12
STOPM
10
DS.SP
SP.WK
Week
1 - 5
STOPW
5
DS.SP
SP.DY
Day
1 - 7
STOPD
7
DS.SP
MIN.S
Minutes to Subtract
0 - 90
MINSUB
60
Summary of Contents for WEATHERMAKER 48/50AJ
Page 103: ...103 Fig 15 Typical Main Control Box Wiring Schematic 48 50AJ AK AW AY Units cont a48 8355 ...
Page 104: ...104 Fig 16 Typical Main Control Box Wiring Schematic 48 50A2 A3 A4 A5 Units a48 8355 ...
Page 105: ...105 TO NEXT PAGE Fig 17 Typical Auxiliary Control Box Wiring Schematic A48 7294 ...
Page 106: ...106 Fig 17 Typical Auxiliary Control Box Wiring Schematic cont a48 8356 ...
Page 107: ...107 Fig 18 Typical 2 Stage Gas Heat Wiring Schematic Size 051 and 060 Units Shown a48 8357 ...
Page 113: ...113 Fig 22 Typical Power Schematic 48 50A2 A3 A4 A5060 Unit Shown ...
Page 114: ...114 SW1 SW2 OR DEHUMIDIFY SWITCH Fig 23 Typical Controls Option Wiring Schematic a48 8361 ...
Page 115: ...115 Fig 24 Typical Small Chassis Component Location Size 020 035 Units a48 8362 ...
Page 116: ...116 Fig 25 Typical Large Chassis Component Locations Size 036 060 Units A48 7302 ...
Page 169: ...169 APPENDIX C VFD INFORMATION cont Fig F Internal Enclosure Fan Replacement A48 7716 ...