Johnson Controls YORK OPTIVIEW CONTROL CENTER, Руководство по эксплуатации

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JOHNSON CONTROLS
110
FORM 160.10-O1
ISSUE DATE: 4/27/2018
SECTION 3 - OPTIVIEW DISPLAY MESSAGES
VSD – DC Bus Voltage Imbalance
The DC link is filtered by many large electrolytic ca-
pacitors, rated for 450 VDC. These capacitors are
wired in series to achieve 900 VDC capability for the
DC link. The voltage must be shared equally from the
junction of the center, or series capacitor connection,
to the negative bus and the positive bus. This center
point should be approximately half of the total DC link
voltage. Most actual bus voltage imbalance conditions
are caused by a shorted capacitor or a leaky or shorted
IGBT transistor in an output phase bank assembly. This
usually indicates the VSD requires service.
VSD – Precharge – DC Bus Voltage Imbalance
This message indicates the same fault as the
VSD-DC
BUS VOLTAGE IMBALANCE , except the condi-
tion occurred during the chiller prelube period.
VSD – High Internal Ambient
Temperature
The internal ambient temperature is monitored by a
component mounted on the VSD logic board with a
trip threshold set for 140°F. Some potential causes for
this shutdown are: internal VSD fan failure, VSD water
pump failure or an entering condenser water tempera-
ture that exceeds the allowable limit for the job. Ad-
ditional causes for the shutdown are:
• Plugged Strainer – The standard 1.5 Y-strainer
contains a woven mesh element with 20 stainless
steel wires per inch; adequate for most applica-
tions. If condenser water is abnormally contami-
nated, the strainer may become plugged. Loca-
tions with special conditions may consider a dual
strainer arrangement with valves to permit clean-
ing of one strainer with the unit still online.
• Plugged Heat Exchanger – In cases where the
strainer plugs frequently, the heat-exchanger may
eventually plug or become restricted to the point
of reduced flow. Back-flush the heat-exchanger by
reversing the two rubber hoses which supply con-
denser water to-from the heat-exchanger. If the
rust cannot be back-flushed, the heat-exchanger
must be replaced.
• Low Condenser Flow – The VSD system requires
eight (8) feet of pressure drop across the heat ex-
changer to maintain adequate liquid flow. If the
pressure drop is less than eight feet, the flow prob -
lem must be corrected or a booster pump must be
added.
VSD – Invalid Current Scale Selection
The position of program jumpers identifies the size of
the VSD employed to the logic board. Jumper posi-
tion allows the VSD to properly scale the output cur-
rent. If the jumper configuration is incorrect, a chiller
shutdown is performed and this message is displayed.
Refer to the
Variable Speed Drive – Service Manual
(Form 160.00-M1) for more information.
VSD – Low Phase (X) Inverter Heatsink
Temperature
(Style D VSD)
This message indicates a heatsink temperature sensor
for Phase A, B, or C (denoted as X above) is showing
a temperature less than 37°F and will cause the chiller
to shut down. Typically, the problem will be an open
thermistor or broken wiring to the thermistor. The nor-
mal thermistor resistance is 10K ohms at 77°F.
VSD – Low Converter Heatsink
Temperature
If VSD part number is 371-02767-XXX (60 Hz) or
371-03700-XXX (50 Hz), a heatsink temperature sen-
sor indicating a temperature of less than 37°F will
cause the chiller to shutdown and display this message.
Typically, the problem will be an open thermistor or
broken wiring to the thermistor. The normal thermistor
resistance is 10K ohms at 77°F.
VSD – Low Phase (X) Inverter Baseplate
Temperature
[Applicable to VSD part number 371-03789-xxx (503
HP 60 Hz; 419 HP 50 Hz)]
The chiller has shutdown because the baseplate tem-
perature for the indicated current phase A, B, or C (de-
noted as X above), has decreased below 37 ºF.
VSD – Low Inverter Baseplate
Temperature
[Applicable to VSD with part number 371-02767-
XXX (60 Hz) or 371-03700-XXX (50 Hz)]
A baseplate temperature sensor indicating a temper-
ature of less than 37°F will cause the chiller to shut
down and display this message. Typically, the prob-
lem will be an open thermistor or broken wiring to
the thermistor. The normal thermistor resistance is 5K
ohms at 77°F.