35
If SP.AV is verified to change properly at 50% and 100%
capacity, then DS.ST= PASS, otherwise DS.ST=FAIL.
EXV Auto-Component Test — The EXV auto-com-
ponent test requires the following conditions:
1. Unit is not shut down due to failure (A152).
2. OAT>70 F.
3. No compressors are on or requested on.
4. A1, B1, and B2 are available on a 75-ton unit, A1, A2,
B1, B2 are available on 90, 105, 120, 130, and 150-ton
units.
The testing screen will display the following:
The EXV auto-component test functions by staging com-
pressor A1, B1, and B2 for a 75-ton unit and A1, A2, B1, B2
for other units, and verifying the superheat is within ±
AC_SH_DB (auto-component test superheat deadband) of the
superheat setpoint (SH.SP).
The auto-component test superheat deadband
(AC_SH_DB) will default to 2 F with a range of 0° to 10 F.
Setting XA.TS=ON will perform the following:
1. Stage compressors A1/B1/B2 for 75-ton unit, A1/A2/B1/
B2 for other units.
2. Allow compressors to run for 5 minutes
3. Verify that SH.A1, SH.A2, SH.B1, and SH.B2 have sta-
bilized to SH.SP ± AC_SH_DB. If all four superheats are
SH.SP ± AC_SH_DB then set PASS status and end test.
4. If any superheat is outside SH.SP ± AC_SH_DB, allow
compressors to run for 5 more minutes
5. Set PASS/FAIL status according to whether each super-
heat has stabilized to SH.SP ± AC_SH_DB and end test
If SH.SP ± AC_SH_DB then XA.ST= PASS, otherwise
XA.ST=FAIL.
If the EXV superheat is not within SH.SP ± SH.DB, the su-
perheat alert will be logged:
Refrigerant Charge Auto-Test (without Liquid
Sensors) —
The refrigerant charge auto test without liquid
sensors requires the following conditions:
1. Unit is not shut down due to failure (A152).
2. OAT>70 F.
3. No compressors are on or requested on.
4. All compressors are available for staging.
The test screen will display the following:
When no liquid sensors are installed, all compressors and
outdoor fans of both circuit A and B are commanded to be ON.
The operator will read OAT, SCT.A, and SST.A, in order to
then compare the values to the A charging chart to determine if
refrigerant in circuit A is properly charged. The operator reads
OAT, SCT.B, and SST.B, in order to then compare the values to
the B charging chart to determine if refrigerant in Circuit B is
properly charged. Thus this is a semi-auto test because the op-
erator intervention is required to determine the test results. No
test results are displayed.
Setting CT.ST=ON will perform the following:
1. Command supply fan ON.
2. Command all A and B Circuit outdoor fans ON.
3. Stage all A and B Circuit compressors ON.
4. Let compressors run 5 minutes.
5. Prompt user to read charging charts
6. Let compressors run 5 minutes.
7. End test.
Refrigerant Charge Auto Test (with Liquid
Sensors) — The refrigerant charge auto test with liquid
sensors requires the following conditions:
1. Unit is not shut down due to failure (A152).
2. Liquid sensors installed and enabled.
3. OAT>75 F.
4. No compressors are on or requested on.
5. All compressors are available for staging.
6. Calculated subcooling both circuit A and B is < -1.5.
7. SST.A and SST.B > AC_SST_M.
The test screen will display the following:
All compressors and outdoor fans of circuits A and B are
commanded to ON. OAT and subcooling (SC.A) will then be
used by the algorithm as described in the steps below to deter-
mine the refrigerant charge level.
AC_SST_M (Auto-Component Minimum SST) is the mini-
mum SST read during a charge determination test. If at any
time during the test, SST.A or SST.B is less than AC_SST_M,
then the test shall be cancelled. AC_SST_M shall default to 40
and have a range of 20 to 100.
Setting CT.ST=ON will perform the following:
1. Command supply fan ON.
2. Command all A and B circuit outdoor fans ON.
EX.TR ON Run EXVs Auto-Test
XT.ST Running
CMPS
Test Status and Timer
SH.SP 12.0 dF EXV Superheat Ctrl SP
SH.A1 11.7 dF Cir A EXV1 Superheat Temp
SH.A2 12.4 dF Cir A EXV2 Superheat Temp
SH.B1 12.4 dF Cir B EXV1 Superheat Temp
SH.B2 12.1 dF Cir B EXV2 Superheat Temp
XA1S Running EXV A1 Auto-Test Status
XA2S Running EXV A2 Auto-Test Status
XB1S Running EXV B1 Auto-Test Status
XB2S Running EXV B2 Auto-Test Status
T064 EXV A1 Superheat Outside Range
T065 EXV A2 Superheat Outside Range
T066 EXV B1 Superheat Outside Range
T067 EXV B2 Superheat Outside Range
CD.TS ON Run Chrg Test without Lqd Sen
CD.ET Running Test Status and Timer
SCT.A 105.3 F Cir A Sat. Condensing Temp
SST.A 50.4 F Cir A Sat. Suction Temp
OAT 66.3 F Outside Air Temp
SCT.B 106.5 F Cir A Sat. Condensing Temp
SST.B 49.8 F Cir A Sat. Suction Temp
CL.TS ON Run Chrg Tst with Lqd Sen
CD.ET Running Test Status and Timer
SC.A –10.3 dF Cir A Subcooling Temp
CS.CA –6.2 dF Calc Cir A Subcooling Temp
CHG.A 0.5 lb Cir A Over/Under Charge
OAT 80.3 F Outside Air Temp
SC.B –10.6 dF Cir B Subcooling Temp
CS.CB –6.6 dF Calc Cir B Subcool Temp
CHG.B –1.3 lb Cir B Over/Under Charge
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