Carrier ComfortLink 6 Series Controls, Start-Up, Operation, Service, And Troubleshooting page 49

LEGEND
A/D — Analog to Digital Converter
CCN — Carrier Comfort Network
CCP — Comfort Link™ Compressor Protection
EMI — Electromagnetic Interference
EMM — Energy Management Module
EWT — Entering Water Temperature
EXV — Electronic Expansion Valve
HPS — High-Pressure Switch
LCW — Leaving Chilled Water
LWT — Leaving Water Temperature
MBB — Main Base Board
MCT_SP — Maximum Condensing Temperature Set Point
MTA — Compressor Must Trip Amps
SCB — Screw Compressor Board
SCT — Saturated Condensing Temperature
SST — Saturated Suction Temperature
TXV — Thermostatic Expansion Valve
WSM — Water-System Manager
*Compressors are equipped with 2 motor winding temperature
thermistors. Verify first that the problem is not a wiring error
before using backup thermistor.
†Manual reset after 1 hour from occurrence.
**Reset automatic first time, manual if repeated on the same date.
††Note that the high-pressure switch should trip before this alert is
generated. Check HPS operation if this alert is generated.
***Maximum 5 power losses at CCP in one hour.
180
160
140
120
100
80
60
40
20
0
0 10 20 30 40 50 60 70 80
CODE NUMBER
1
2
3
4
5
6
7
8
LEGEND AND NOTES FOR TABLE
90 100 110 120 125
(DISCHARGE-SUCTION) PRESSURE, PSI
Fig. 20 — Oil Pressure Set Point 2 Calculation
Table 33 — Illegal Configurations (Alarm A151)
ILLEGAL CONFIGURATION DESCRIPTION
Unit type outside range of 1-5
Number of compressors in Circuit A outside range of 1-2
Number of compressors in Circuit B outside range of 1-2
Invalid FAN.S or HPCT Selection
Air-cooled chiller with Low Temperature Brine fluid (FLUD = Low Brine)
Water-cooled chiller configured for air-cooled head pressure control type (HPCT)
Air-cooled chiller with condenser pump control enabled
Air-cooled chiller with condenser fluid sensors enabled
49
NOTES:
1. Low Oil Pressure Alert Criteria and Set Points
Where: P = Discharge Pressure, P
d
P = Oil Pressure and P = Economizer Pressure
o e
Two oil set points are used by the control for the Low Oil Pressure
alert trip.
Oil Set Point 1 is defined as:
a. If P < 35, then Oil Set Point 1 = 10 psig.
s
b. If P > 35 and < 51, then Oil Set Point 1 = 12.5 psig.
s
≥ 51, then Oil Set Point 1 = 15 psig.
c. If P
s
Oil Set Point 2 (see Fig. 20) is defined as:
a. If (P – P ) < 125, then Oil Set Point 2 = 0.235 x (P
d s
0.588
b. If (P – P ) > 125 and < 165, then Oil Set Point 2 = 2.0 x
d s
(P – P ) – 220.0
d s
) ≥ 165 then Oil Set Point 2 = 0.6364 x (P
c. If (P – P
d s
5.0
2. (P – P ) is the Oil pressure differential displayed as items DO.A1
o e
and DO.A2 (Pressures mode under sub-mode PRC.A) for
Circuit A and DO.B1 and DO.B2 (Pressures mode under sub-
mode PRC.B) for Circuit B.
3. Alert criteria is based on operating time.
a. On time less than 5 seconds oil pressure is ignored.
b. On time between 5 and 120 seconds, the alert will be gener-
ated if the following condition is true for 3 consecutive read-
ings:
(P – P ) < [15 psig/120 sec.] x [Compressor Run Time in sec.]
o e
c. On time greater than 120 seconds the alarm will be generated
if one of the following conditions is true:
(P – P ) < Oil Set Point 1 for 15 seconds.
o e
(P – P ) < Oil Set Point 2 for 15 seconds.
o s
130 140 150 160 165 170 180 190 200 210 220 230 240
= Suction Pressure.
s
– P ) +
d s
– P ) +
d s