This manual is prepared to provide all the necessary information of
installation, operation and maintenance of the latest generation of
Dunham-Bush air-cooled chillers with scroll compressors.
In order to be able to make full use of the manual, you must first determine
your unit model number from the unit name plate.
Dunham-Bush package has been manufactured under a stringent quality
control system. Each packaged chiller is performance tested at the factory
at the specified field operating conditions as a final verification of reliability.
If the package is installed, operated and maintained with care and attention
to the instructions contained here in, it will yield many years of satisfactory
service.
It is assumed that the reader of this manual and those who install, operate
and maintain the equipment have a basic understanding of the principles of
air conditioning, refrigeration and electrical controls.
TABLE 1.1 PRODUCTION IDENTIFICATION
AC D S 030 - AR G S
Air Cooled Packaged Chiller
Direct Expansion Evaporator
Scroll Compressor
Nominal Capacity in Tons
(ARI Condition)
S- Standard Fan
F- Low Noise Fan
V- Compressor Jacket
M- Low Noise Fan &
Compressor Jacket
R410A
AN- 208-230V/3pH/60Hz
AR- 460V/3pH/60Hz
- 3 -
1.0 INTRODUCTION
1.1 PHYSICAL DATA
MODEL ACDS 010 020 030 040 050 060 070 080
NOMINAL CAPACITY TONS
NOMINAL POWER INPUT KW
RPM
MIN. % UNIT CAPACITY REDUCTION
NO. OF REFRIGERANT CIRCUIT
WATER CONNECTOR INCH[MM]
NOM. WATER FLOW / PD
(GPM)/(FT IN WG) [m³/hr / kPa]
Note: Nominal capacity is based on evaporator LFT 44°F and condenser ambient 95°F, actual capacity depends on the specified operating
conditions.
56 (6)
- 5 -
2.0 INSTALLATION
2.1 GENERAL
The ACDS chiller is designed to cool water or
other non-corrosive liquids. Water is circulated
through the direct expansion evaporator where it
is cooled to the desired temperature and then
circulated to cooling coils for air conditioning, or to
other types of heat exchangers for process
cooling.
Care should be taken to ensure that the
equipment is properly installed and adjusted. An
installer or operator should first be familiar with
the information in this manual.
2.2 INSPECTION
When the equipment is delivered, it is important
that the following inspection be completed in the
presence of the carrier's representative:
1. Check all crates and cartons received against
the Bill of Lading/Shipping Papers to be sure
they tally.
2. Check the model number and the electrical
characteristics on the nameplate to determine
if they are correct.
3. Check for freight damage, shortages or other
discrepancies and take note of them on the
delivery receipt before signing.
Should any damage be found, a damage
claim should immediately be filed by the
purchaser against the delivering carrier as all
shipments are made at the purchaser's risk.
2.3 RIGGING
2.3.1 GENERAL
Each unit has been carefully tested and
packed at the factory where every care is
taken to ensure that the unit reaches you
in perfect condition. It is very important
that the riggers and movers use the same
care and precaution in moving the
equipment into place. Make sure that
chains, cables, or other moving
equipment are placed so as to avoid
damage to the unit or piping. The
refrigerant piping should not be used as a
ladder or as a handle. Do not attach a
chain hoist sling to the piping or
equipment. Move the unit in an upright
position and let it down gently from trucks
or rollers.
2.3.2 RIGGING AND MOVING
Any unit mounted on skids may be moved
with a forklift, but care must be taken not
to damage the unit with forks. The skids
should not be removed until the unit is at
its final location.
The ACDS model can be lifted by the
method showing in Figure 2.3.2.
2.4 SPACE REQUIREMENTS
AND CLEARANCE
2.4.1 GENERAL
The dimensional data and clearances that
follow are useful for determining space
requirements. The unit should be placed
to make the clearance noted available for
proper servicing. Failure to allow such
clearance will cause serious problems
and result in higher costs for operation,
maintenance and repair.
2.4.2 ACDS
The dimensional data are shown in
Figure 2.4.2B and space requirements
are shown in Figure 2.4.2A. The most
important consideration which must be
taken into account when deciding on the
location of an air cooled equipment, is the
provision for supply of ambient air to the
condenser, and removal of heated air
from the condenser area. When this
essential requirement is not provided, it
will result in higher condensing
temperatures, which will cause poor
operation, higher power consumption and
eventually failure of equipment. Units
must not be located in the vicinity of
steam, hot air or fume exhausts.
Another consideration which must be
taken into account is that the unit should
be mounted away from noise sensitive
spaces and must have adequate support
to avoid vibration and noise transmission
into the building. Units should be
mounted over corridors, utility areas, rest
rooms or other auxiliary areas where
sound levels are not an important factor.
Sound and structural experts should be
consulted for recommendations on critical
installations.
- 6 -
2.0 INSTALLATION
FIGURE 2.3.2 ACDS RIGGING
ACDS 010
ACDS 020
- 7 -
2.0 INSTALLATION
ACDS 030, 040, 050, 060, 070
ACDS 080, 090, 100, 120,
ACDS 135, 150, 165, 180
- 8 -
2.0 INSTALLATION
FIGURE 2.4.2B DIMENSIONAL DATA
ACDS 010
- 9 -
2.0 INSTALLATION
ACDS 020
- 10 -
2.0 INSTALLATION
ACDS 030
- 11 -
2.0 INSTALLATION
ACDS 040
- 12 -
2.0 INSTALLATION
ACDS 050, 060, 070
- 13 -
2.0 INSTALLATION
ACDS 080, 090
48 [1219.200 mm]
60.5 [1537.400 mm]
(BOTTOM)
POWER ENTRY
AIR FLOW
24 [609.600 mm]
DOOR SWING
88 [2235.600 mm]
AIR FLOW
48 [1218.800 mm]
CONTROL BOX ACCESS
TOP VIEW
AIR FLOW
88
84 [2134]
FRONT VIEW
6 NOS OF n 2.9 [73mm] LIFTING
HOLES ON BOTH SIDE OF THE FRAME
12 [304.800 mm]58 [1467.100 mm]66 [1675.100 mm]
148 [3747.000 mm]
LEFT VIEW
MOUNTING HOLES
6 NOS OF 3/4" (19)
FOR SPRING ISOLATORS
12 [300.300 mm]
REAR VIEW
88 [2236.711 mm]
- 14 -
2.0 INSTALLATION
ACDS 100, 120
- 15 -
2.0 INSTALLATION
ACDS 135, 150
WATER IN CONNECTION [3.5"] NOMINAL DIA
OPTIONAL-WELDED FLANGE CONNE CTION
DETAIL A
33 [836.000 mm]
WATER OUT CONNECTION [3.5"] NOMINAL DIA
OPTIONAL WELDED FLANGE CONNECTION
Approx.
44 [1119.700 mm]
Approx.
9 [219.500 mm]
NOTES:
4. WATER PIPING TO BE SUPPORTED TO MINIMIZE LOAD ON UNIT.
2. ALLOW 60 [ 1254 ] CLEARANCE AT CONTROL PANEL END OF UNIT FOR SERVICES.
3. USE MINIMUM 36 [ 914 ] FLEXIBLE CONDUIT TO CONTROL BOX TO ISOLATE UNIT.
1. ALL DIMENSIONS ARE IN INCHES AND MILIMETERS.
48 [1216.800 mm]
(BOTTOM)
POWER ENTRY
60.5 [1536.600 mm]
AIR FLOW
24 [609.200 mm]
DOOR SWING
88 [2237.600 mm]
CONTROL BOX ACCESS
AIR FLOW
.
POWER ENTRY
TOP VIEW
84 [2134]
88 [2235]
(BOTTOM)
6 NOS OF ?2.9 [? 73.200 mm] LIFTING
HOLES ON BOTH SIDE OF THE FRAME
MOUNTING HOLES
6 NOS OF 3/4" (19)
FOR SPRING ISOLATORS
FRONT VIEW
30 [762.000 mm]
83 [2101.850 mm]83 [2101.850 mm]30 [762.000 mm]
226 [5740]
LEFT VIEW
A
48 [1219.200 mm]
AIR FLOW
REAR VIEW
93 [2357.500 mm]
- 16 -
2.0 INSTALLATION
ACDS 165, 180
WATER IN CONNECTION [3.5"] NOMINAL DIA
OPTIONAL WELDED FLANGE CONNECTION
2. ALLOW 60 [ 1254 ] CLEARANCE AT CONTROL PANEL END OF UNIT FOR SERVICES.
NOTES:
1. ALL DIMENSIONS ARE IN INCHES AND MILIMETERS.
DETAIL A
WATER OUT CONNECTION [3.5"] NOMINAL DIA
33 [836.000 mm]
4. WATER PIPING TO BE SUPPORTED TO MINIMIZE LOAD ON UNIT.
3. USE MINIMUM 36 [ 914 ] FLEXIBLE CONDUIT TO CONTROL BOX TO ISOLATE UNIT.
The foundation must be level for proper
operation and functioning of controls and
provision must be made for supporting
the individual load points as shown in
Figure 2.5.1, Roof mounted units must be
supported on adequate steel structures. If
units are located on the ground level, a
concrete plinth is recommended.
2.6 VIBRATION ISOLATION
Under certain critical conditions, it may be
necessary to install vibration isolators under the
base of the Packaged Chiller.
FIGURE 2.5.1 FLOOR LOADING DIAGRAM
ACDS 010 ACDS 020
POINT LOAD LOCATION
MODEL
ACDS
010 31 (787) 2 (51) 54 (1372) 2 (51)
020 31 (787) 2 (51) 92 (2337) 2 (51)
A B C D
Rubber-in-shear or spring vibration isolators are
offered as optional items. When spring isolators
are used, flexible connectors must be installed in
the water piping system and in the refrigerant
lines of split systems. Kindly note that: These
flexible connectors must be suitable for the fluid
and pressures involved.
When using flexible connectors in refrigerant
piping, they must be mounted in the refrigerant
discharge and liquid lines close to the packaged
chiller, in a horizontal position and parallel to the
compressor crankshaft.
All piping which is external to the packaged chiller
must be supported by spring mounted hangers
and any piping which goes through the wall,
ceiling or floor should be properly pivoted to
prevent transmission of piping vibration to the
structure.
After the unit has been leveled, the
external water piping may be set up. Be
sure that the water piping is connected to
the corresponding connectors. The wateroutlet connection of the evaporator is
closest to the expansion valve (refrigerant
circuit) end.
Water flow through the evaporator must
remain constant for proper chiller
operation. Water pressure gauges are
recommended to check the water
pressure and flow rate in the system,
before and after the evaporator, and to
determine if variations occur in the
evaporator and system. When installing
pressure taps to measure the amount of
pressure drop across the water side of
the evaporator, the taps should be
located at least twenty-four (24) inches
[610mm] downstream from any
connections (flange, elbow, etc.) in the
water piping.
There are many piping and control
systems which may be used to ensure
constant water flow through the
evaporator. A typical system is shown in
Figure 2.7A. A three-way motorized
valve, which operates in response to the
discharge air temperature of the cooling
coil, is used.
Another system which is sometimes used
consists of a two-way modulating control
valve, which also responds to the
discharge air temperature of the cooling
coil, used with a spring loaded bypass
regulating valve as shown in Figure 2.7B
The bypass valve must be set to ensure
full flow of circulating chilled water when
the modulating valve is completely
closed.
Other systems are noted in the ASHRAE
Handbook and may operate equally well.
Whatever the system is selected, the
water flow must be constant.
2.7.2 WATER CONNECTIONS Multiple Packaged Chillers
Multiple unit package chillers have been
successfully applied to parallel and series
piping systems for years. Special
attention, however, must be given to the
particulars involved for each application
or serious operational problems can
result. The following guidelines should be
followed for multiple unit application.
It is assumed that the chilled water flow
rate is constant.
2.7.2.1 Parallel Chilled Water Flow Units
Method A: Both units operate
simultaneously, modulating with load
variations. Each packaged chiller
operating thermostat senses the return
water temperature using standard
controls (See Figure 2.7C). The set point
of each thermostats will be set to
maintain the desired unloading. In
addition to that, for each chiller package,
the suction sensing hot gas by-pass
valve provides modulating capacity
reduction from 100% to approximately
30% on single compressor models with
hot gas by-pass.
Method B: Install units the same as
Method A, but add a third thermostat in
the return water, as shown in Figure
2.7E. This thermostat will be set to cycle
off one of the units when the load drops
below 50%. When this condition is
reached, the leaving mixed water
temperature will rise, causing the return
water temperature to rise and the unit
operating will load up. The "off" unit is
sequencing to start again before full
system load temperature is reached.
This system will be as stable as Method
A, in operation, but in normal airconditioning applications, this is not
detrimental. The advantage of Method B
is a better part load efficiency. Also a
lead-lag control can be added.
- 21 -
2.0 INSTALLATION
FIGURE 2.7A
FIGURE 2.7B
FIGURE 2.7C
FIGURE 2.7E
FIGURE 2.7D
- 22 -
2.0 INSTALLATION
2.7.2.2 Series Chilled Water Flow Units
Units should be equally sized. The
upstream unit will carry a larger load
because it cools higher temperature
water. The thermostats sense inlet
water temperatures. (See figure 2.7D).
The number 1 unit thermostat will
unload or cycle off the packaged chiller
before unloading occurs of the Number
2 unit.
2.7.3 WATER QUALITY
Evaporators used in this packages is
made of steel and copper and are
suitable for operation with wellmaintained water systems. However, if
the water used in evaporator is corrosive,
high in mineral content or entrained
solids, the water can reduce the
performance and even damage the heat
exchangers. Therefore, it may be
necessary to obtain the service of a water
treatment consultant and to provide and
maintain water treatment. This is
particularly important with glycol systems
and with cooling tower loops.
2.8 ELECTRICAL
CONNECTIONS
2.8.1 GENERAL
All units are wired as completely as
possible at the factory prior to delivery.
The connections which must be made by
the installer are to the main power
source, starting equipment and
interlocking the satellite equipment. In
connecting power wiring to the unit, the
following precautions should be taken:
- All field wirings are to be in accordance
with the National Electrical Code and
state and local codes.
- All wirings are to be checked for damage
and all terminal connections are to be
tested for tightness. Unit terminal blocks
are to be connected with copper
conductors only and sized per ampacity
listed on unit data plate.
- The power supply should match the unit
nameplate in volts, phase and Hertz.
Voltage must be within ±10% of
nameplate value and voltage imbalance
between phases must not exceed 2%
2.9 REQUEST FOR START-UP
REPRESENTATIVE
Start-up service is an option upon request when
an order for the unit is placed. If you request for
start-up service, then after the installation has
been completed and checked, a written notice
shall be given to the Dunham-Bush
representative. Following receipt of written notice,
a representative will be sent to the customer. The
purchaser should have competent service and
operating personnel in attendance to assist in the
work involved, and also to be trained in the
operation and maintenance of this unit.
The representative will inspect the installation to
determine whether it meets Dunham-Bush
requirements, perform the initial start-up of the
installation determine whether it is in satisfactory
operating condition, and instruct specified
customer personnel in its operation and
maintenance for the length of time specified in the
purchase contract.
- 23 -
3.0 OPERATION
3.1 GENERAL
The unit should be started up only by a
refrigeration technician who is familiar with the
accepted operation practices for refrigeration
systems.
Use the scroll unit start-up report, to record all
temperature, pressure, electrical readings and
control settings. A copy must be forwarded to
Dunham-Bush service department, before
warranty will be honored.
3.2 UNIT PIPING
See Figure 3.2.1 for typical unit piping
schematics.
3-3 AIR COOLED PACKAGES
START-UP
The unit is ready for start-up when the following
procedures have been completed:
1. Water piping for the evaporator is installed
and tested.
2. Electrical connections are made and properly
fused.
3. Unit has been leak tested, leaks corrected
and charge completed.
4. Compressor crankcase heater(s) has been
energized for a minimum of 24 hours.
5. Calibrated refrigerant gauges have been
connected to the suction and discharge ports.
6. Turn On the chilled water pump, check
direction of rotation and adjust the water flow
through the evaporator to the specified flow
rate. Bleed off all entrained air.
7. Manually energize the fan starters and check
the fan rotation. Fans should pull air through
the condenser coil and discharge vertically
upwards. Rotation can be changed on 3phase motors by interchanging only two wires
on the main terminal block.
8. Check all refrigerant valves to be sure they
are open.
3.4 SYSTEM START-UP
1. Before starting the compressor(s), check all
three phases of supply voltage, of all legs of
the motor. They must be within ±10% of the
nameplate voltage.
2. Start compressor(s), check the gauges and
note if the pressures are within the prescribed
limits.
3. Check the refrigerant sight glass to be sure it
is free of bubbles. If not, charge as specified
per section 4.8 Charging.
4. Shut the compressor down and check the
compressor crankcase sight glass for oil level.
It should be between 1/2 to 3/4 of the
complete sightglass. If not, see Section 3.5
Lubrication.
5. Restart the compressor. After an hour of
operation the expansion valve superheat
setting should be checked, it should be
between 8°F [4.4°C] and 10°F [5.6°C] at full
load design conditions. In some instances, it
will be necessary to lower the superheat
setting to ensure proper distribution. Turn the
TX valve adjustment stem clockwise to
increase the superheat setting and
counterclockwise to decrease the setting. Be
sure and allow ample time between each
adjustment for the system to rebalance.
6. The temperature of the chilled water both in
and out, should be checked to insure the unit
is operating within the desired temperatures.
3.5 LUBRICATION
3.5.1 OIL LEVEL
A properly operated unit should run with
the compressor crankcase warm to touch.
Check oil level frequently to see that a
sufficient amount of oil remains in the
crankcase. Compressor oil level can be
checked by the sight glass. To make sure
that proper oil level is observe, operate
the compressor for 15 minutes, then stop
the compressor. Oil should appear from
1/2 to 3/4 in the sight glass with the
compressor stopped.
9. Proceed to section 3.4 System Start-Up.
- 24 -
3.0 OPERATION
FIGURE 3.2.1 TYPICAL PIPING SCHEMATIC
ACDS 010, 020, 030
- 25 -
3.0 OPERATION
ACDS 040, 050, 060, 070
- 26 -
3.0 OPERATION
ACDS 080, 090, 100, 120
- 27 -
3.0 OPERATION
ACDS 135, 150
- 28 -
3.0 OPERATION
ACDS 165, 180
- 29 -
3.0 OPERATION
3.5.2 OIL TYPE
If the oil becomes discolored indicating
contamination, the contamination can be
take care of by installing a new filter-drier
in the liquid line and changing the oil.
WARNING:
Use Only Dunham-Bush Approved
Refrigeration Oil, Warranty Will Be
Void If Other Than Approved Oil Is
Used. It is recommended to change oil
annually to prolong the compressor
life-time.
Oil charge for a complete recharge shown
in the following table. Oil type and
approved oils are also listed for each
compressor. After recharge the oil level
3.6 SYSTEM FLOW RATE
The quantity of chilled water being circulated can
be estimated by determining the water pressure
drop through the evaporator by reading GPM
[L/S] from the appropriate pressure drop curve.
(See Figure 3.6)
An alternate method of determining GPM [L/S]is
to measure pressure difference from pump inlet to
outlet and read GPM [L/S] from pump curve.
Water flow rate must not vary more than ±10%
from design flow rate.
3.7 SYSTEM CONTROL
3.7.1 CAPACITY CONTROL
should be maintained per section 3.5.2.
COMPRESSOR MODEL OIL CHARGE (L) APPROVED OIL
HLH 068
SH 140
SH 180
SH 240
SH 300
SH 380
1.6 PVE
3.3
6.7
7.2
POE
(160SZ)
The standard system capacity control
operates as follows:
- As the chiller load initially drops, the
suction of the compressor(s) starts
dropping proportionately, thus
balancing minor load variations.
- Variation of unit capacity in response to
system load requirements is controlled
by an operating thermostat, which
monitors the return water temperature.
- On multiple compressor units, capacity
is controlled by compressor staging.
Refer to Table 3.7.1 to determine the
capacity control scheme for your
specific unit.
TABLE 3.7.1 CAPACITY CONTROL
COMPRESSOR CYLINDER UNLOADING
AND STAGING SCHEDULE
ACDS 010, 020, 030
COMPRESSOR OFF 0.0%
COMPRESSOR 1 ON 100% 50.0%
ACDS 040, 050, 060, 070, 080, 090, 100, 120
COMPRESSOR OFF 0.0%
COMPRESSOR 1 ON 100% 25.0%
COMPRESSOR 2 ON 100% 50.0%
COMPRESSOR 3 ON 100% 75.0%
COMPRESSOR 4 ON 100% 100.0%
ACDS 135, 150, 165, 180
COMPRESSOR OFF 0.0%
COMPRESSOR 1 ON 100% 16.7%
COMPRESSOR 2 ON 100% 33.3%
COMPRESSOR 3 ON 100% 50.0%
COMPRESSOR 4 ON 100% 66.7%
COMPRESSOR 5 ON 100% 83.4%
COMPRESSOR 6 ON 100% 100.0%
SOLID-STATE OPERATING
3.7.2
THERMOSTAT
3.7.2.1 General
A four-stage solid-state operating
thermostat, FSE, is used on all AC
packages. The opstat senses return
chilled water or air temperature and by
staging and/or unloading compressors is
able to control leaving chilled water or air
temperature to a narrow band of
temperature.
3.7.2.2 Opstat Settings
Each four-stage electronic opstat is
factory, adjusted to your specified
conditions, A field check of the controller
may be made by first determining your
design range (R). To determine the
range of a water chiller, subtract the
design leaving water temperature (TLW)
from the return water temperature
(TRW) (R =TRW-TLW).
ACDS CAPACITY
- 30 -
3.0 OPERATION
The standard range is 10°F [5.6°C]. To
determine the range of a condensing
unit, subtract the design no load return
air temperature (TNL) from the design
full load return air temperature (TFL) (R=
TFL- TNL). The standard range is 6°F
[3.3°C].
Set point of the opstat should be your
design leaving chilled water temperature
(TLW) for water chillers. The standard
adjustment range for AC units is 32 to
104°F [0° to 40°C].
The location of setting knob is shown in
Figure 3.7.2A.
Step Temp adjusts the temperature
range per stage in degrees F. To
determine TRB. For a standard
condensing unit TRB= 0.25 x R. Check
the dial setting on the opstat. The
approximate setting of Step Temp is
shown in the Figure 3.7.2B by the Step
Temp should be changed by an
authorized serviceman only.
3.8 ELECTRICAL CONTROLS
MCCB/MCB/MMS - Main Circuit Breaker
This is an automatic, calibrated, ambient
compensated, magnetic trip circuit breaker, which
provides both direct line-break compressor
branch circuit. short circuit locked rotor and
overload protection. It has a manually operable
handle for compressor circuit disconnect, and an
auxiliary NO. switch (optional) which interrupts the
115V compressor control circuit when the breaker
opens.
M - Contactor (Compressor and Fan
Motor)
The contactor, operated by the control circuit,
provides power individually to the compressor and
fan motors. Contactors are used either singly or in
parallel pairs for across-the-line start
(simultaneous operation). These devices are amp
rated to handle both rated load amp and locked
rotor amps.
CR - Relays (Miscellaneous Control)
These relays provide the necessary circuit logic
for lock-in, lock -out and transfer functions.
HTR - Crankcase Heater
Energized continuously as long as control circuit
power disconnect switch (not supplied with the
unit) is closed and compressor is off. This heater
maintains crankcase temperature above the
system temperature during the compressor off
cycle, preventing refrigerant migration into the
crankcase and consequent compressor damage.
SOLi.) Liquid Line Solenoid Valve
Closes when the compressor(s) is off to
prevent any liquid refrigerant from
accumulating in the chiller during the off
cycle.
ii.) Discharge Solenoid Control (Optional)
This function is used in low ambient
application. Discharge solenoid is turn off to
reduce condensing surface and to increase
head pressure.
OL - Motor Overload
(Manual Reset)
For AC the compressor is protected by overload
relays utilizing quick trip, ambient compensated
heaters. The overload relays are manually reset.
OUVR - Over Under Voltage Relay
(Optional)
Protects the unit from the following electric supply
malfunctions: over voltage, under voltage, please
reversal, single phasing and phase imbalance. If
the OUVR trips, a control relay will de-energize
and open the control circuit. A red LED trip light,
located on the OUVR, will indicate a supply
malfunction. Tile OUVR is a manual reset control
device.
1- Display: shows the value measured by the connected sensor. In the event of alarm condition the
sensor value will be displayed alternately with the codes of the active alarms. When programming the
instrument, the display shows the parameter codes being introduced and their values.
2- Decimal Point LED: lights up when the controlled parameter is displayed.
3- Reverse LED: flashes when at least one relay working in the "Reverse" mode is active. The Led
flashes as many times as the number of active 'reverse' relays. There is a two seconds' pause
between a flashing stage and the next one.
4- Direct LED: flashes when at least one relay working in the "Direct" mode is active. Its working logic is
the same as the "Reverse" LED.
5- SEL Button: displays and/or allows you to select the Set-point. If pressed for 5 seconds together with
PRG/MUTE it allows you to enter the password and the configuration parameters (having a "Cxx" type
code).
6- PRG/Mute Button: if pressed for 5 seconds it allows you to access the menu of the more frequently
used parameters (having a "Pxx" type code). In the event of alarm condition, it silences the buzzer
and, if pressed after the cause that determined the alarm has disappeared, it resets any other alarm. It
completes the programming procedure storing all the values of the modified parameters.
7- Button Δ: increases the value of the set-point or that of any other selected parametel:
8 - Button ∇ : decreases the value of the set-point or that of any other selected parametel: In NTC input
versions it can display the value of the second sensor (holding "Down" pressed while the display
shows the value of the main sensor).
Note: for Infrared Universal, Series models, please refer to the table at the end of the manual
4.2.1 TYPICAL CONTROL SEQUENCE WITH 2 STAGE OPERATING
THERMOSTAT AT 10°C RETURN WATER SETPOINT, 3.0°C DIFFERENTIAL
- 34 -
4.0 ELECTRICAL
4.2.2 KEYPAD OPERATION
1) Set-point display:
Press [SEL] key to display set-point.
2) Set-point modification:
Press [SEL] key for few sec to change
St1 setpoints. Release [SEL] key, actual
set-point value flashes. Use [up arrow] or
[down arrow]key to change value. Press
[SET] key to confirm new value.
3) "P" Parameters modification:
Press [PRG/mute] key for 5 sec allows
you to access the most frequent used
parameters ("Pxx" type code).Use [up
arrow] or [down arrow] key to require
parameter. Press [SEL] key to display this
parameter. Use [up arrow] or [down
arrow] key to set value. Press [SEL] key
to confirm. Repeat procedure for other
parameters. Press [PRG/mute] key to
store modified data and go back to
normal operation.
4.2.3 IR32 ELECTRONIC THERMOSTAT PARAMETERS LIST
Par. Description Min. Max. Default Fac. Set
St1 Set Point 1 min probe max probe 20 6
St2 Set Point 2 (Modes 6,7,8,9) min probe max probe 40 NA
CO Operation Mode 1 9 2 1
Setting Differentials
P1 Set Point 1 Differential (absolute value) 0.1 99.9 2 2
P2 Set Point 2 Differential 0.1 99.9 2 NA
P3 Dead Zone Differential (Modes 3,4,5) (absolute value) 0 99.9 2 NA
C6 Delay time (sec) btw energization of different relays 0 999 5 120
C7 Min time (min) btw energization of the same relay 0 15 0 5
C8 Min off time (min) of the same relay 0 15 0 3
C9 Min on time (min) of the same relay 0 15 0 0
Outputs Status in the event of sensor alarm:
0 = All relays de-energized
C10
1 = All relays energized
2 = DA relays energized, all others de-energized
3 = RA relays energized, all others de-energized
Output Rotation: (Modes 1,2,6,7,8 only)
0 = No rotation
C11
1 = Standard rotation
2 = 2+2 rotation (compressor on relays 1 & 3)
3 = 2+2 rotation (valve normal open)
4) "C" Parameters modification:
Press [SEL] key + PRG/mute] key for 5
sec allows you to enter password and
configuration parameters ("Cxx" type
code). Display show 0. Select password
by pressing [up arrow] key until 22 or 77
display. Press [SEL] key to confirm. Code
C0 displayed if password is correct else
repeat procedure. Use [up arrow] or
[down arrow] key to desire parameter.
Press [SEL] to confirm. Use [up arrow] or
[down arrow] key to desire value. Press
[SEL] to confirm. Repeat procedure for
other parameters. Press [PRG/mute] key
to exit.
5) Alarm Handling:
In the event of alarm condition, press
[PRG/mute] key to silence the buzzer. If
pressed after the cause of alarm
disappeared, it resets any other alarm.
6) Second Probe Display:
For NTC input versions, 2nd probe value
can be displayed by pressing [down
arrow] key while the main probe value is
displayed.
-2 2 0.5 0.5
0 3 0 0
0 7 0 0
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4.0 ELECTRICAL
Par. Description Min. Max. Default Fac. Set
C11 Output models only (A and Z)
4 = Rotation of relays 3 & 4 (No rotation for 1 & 3)
5 = Rotation of relays 1 & 2 (No rotation for 3 & 4)
6 = Separate rotation of coupled relays 1-2 & 3-4
7 = Rotation on relays 2,3,4 (No rotation for 1)
NTC probe : 0 = normal function, 1= invert function,
(instrument display NTC2 and control on NTC1)
P14 Probe calibration or offset -99 99.9 0 0
C15 Analog Input min.scaling value -99 C16 0 NA
C16 Analog Input max.scaling value C15 999 100 NA
C17 Probe response time (noise filter) 1 14 5 5
C18 Temperature unit: 0 = C, 1 = F 0 1 0 0
C19 2nd Probe: NTC only, Mode 1 or 2
0 = no modification on std. Mode
1 = differential mode (NTC1 - NTC2)
2 = summer offset
3 = winter offset
4 = active offset with Dead zone P2
C21 Set point 1 min. limit -99 C22 min. probe -50
C22 Set point 1 max. limit C21 999 max. probe 90
C23 Set point 2 min. limit -99 C24 min. probe -50
C24 Set point 2 max. limit C23 999 max. probe 90
Alarms
P25 Low temp. alarm set point -99 P26 min. probe -50
P26 High temp. alarm set point P25 999 max. probe 90
P27 Alarm hysteresis 0.1 99 2 2
P28 Alarm delay, min 0 120 60 60
C29 Digital input 1 configuration (CO different from 6,7,8)
In case of alarm the status of relays depends on C31
0 = non active input
1 = immediate alarm with automatic reset
2 = immediate alarm with manual reset
3 = delay alarm (P28) with manual reset
4 = on/off of the control
C30 Digital input 2 configuration (IRDR only)
option as for C29
C31 Outputs Status in case of alarm condition detected
via digital input:
0 = All relays de-energized
1 = All relays energized
2 = DA relays energized, all others de-energized
3 = RA relays energized, all others de-energized
Others
C32 Unit address (for serial connection) 1 16 1 1
Special Parameters
C33 Special mode of operation: 0 = No, 1 = Yes
DO NOT MODIFY THIS PARAMETER
Set and programmed starting mode C0 before
modifying C33
C50 Keypad(KP) and Remote Control(RC) activation:
0 = KP off, RC on (only type P parameters)
1 = KP on, RC on (only type P parameters)
2 = KP off, RC off
3 = KP on, RC off
4 = KP on, RC on (all parameters)
C51 Remote IR controller activation code 0 120 0 0
0 7 0 0
0 1 0 0
0 4 0 0
0 4 0 4
0 4 0 NA
0 3 0 0
0 1 0 0
0 4 4 3
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4.0 ELECTRICAL
4.2.4 IR32 ELECTRONIC THERMOSTAT TROUBLESHOOTING
Code Description Cause Control Action Reset Remedies
Er0 Sensor error faulty sensor depends on C10 R: automatic
V: manual
Er1 Sensor NTC2
error
faulty sensor if C19=1 & Mode
=1 or 2
R: automatic
V: manual
see Er0
Er2 Memory error voltage drop
during
Stoppage R: automatic
V: manual
programming
stage,
memory
damaged by
electromagnetic
interference
Er3 Alarm via
external contact
on digital input
contact linked to
digital input is
open
depends on C31 R: depends
on C29 &
C30
V: manual
Check connection. Check
sensor signal
Check connection. Check
sensor signal
Reset factory-set values.
Turn off controller, turn on
again holding [PRG/mute]
key
Check C29, C30, C31 &
P28.
Check the external contact
Er4
Er4 High
temperature
alarm
temp > P26 for a
time interval >
P28
Nil R: automatic
V: manual
Check P26, P27 & P28.
Er5 Low
temperature
alarm
temp < P25 for a
time interval >
P28
Nil R: automatic
Check P26, P27 & P28.
V: manual
NOTE:
R = Control action
Resetting the instrument means to restore normal operating conditions after the cause that determinied the alarm has been cleared.
V = Display
Display and buzzer. Display reset means that normal display of usual values is restored.
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4.0 ELECTRICAL
4.3 VISION 2020i
CONTROLLER AND
TERMINAL
Vision2020i controller is equipped with a user
friendly 132x64 pixels back-lit graphic display
terminal. It is connected with controller through
telephone cable. This terminal allows carrying out
all program operations. The user terminal allows
displaying the unit working conditions,
compressor run times, alarm history at any time
and modifying the parameters. The terminal also
has an automatically self-test of the microcontroller on system start-up. Multiple messages
will be displayed by automatically scrolling from
each message to the next. All of these messages
are spelled out in English language on the LCD
screen.
4.3.1.1 The fifteen polycarbonate buttons:
a) Seven polycarbonate buttons at top
row
Button Description
INPUT STATUS
OUTPUT
STATUS
COMPRESSOR
STATUS
SETPOINT Displays the status of set points.
CLOCK/
SCHEDULE
ALARM HISTORY Display the alarm history.
Displays the analog inputs and
digital inputs status measured by
the probes/sensors.
Displays the relay outputs and
analog outputs status.
Displays the status of Compressor
1, 2 and so on.
Displays the date, time and day.
4.3.1 DBG1 OPERATOR KEYPAD
The DBG1 operator keypad consists of
15 polycarbonate buttons:
Figure 4.3.1 : Vision 2020i keypad
The top right ‘Authorization’ button is for
password log in to gain authorization, to
the access setting menu.
The top left six operator buttons
functions are to view status only, except
the ‘Setpoint’ button also allows setting
changes after gained authorization.
The three buttons at the bottom left are
to access different level of setting
changes.
These are 'User', 'Technician' and
'Factory' levels, from left.
It can only be access depend on the
password level. The higher password
can access the lower password level's
setting and not vice versa.
AUTHORIZATION To log in the level of passwords.
b) Eight polycarbonate buttons at
bottom row
Button Description
USER User Control Changeable Settings.
TECHNICIAN
FACTORY Factory Control Changeable Settings.
MENU
ALARM RESET
UP
DOWN See the UP arrow
ENTER
Technician Control Changeable
Settings.
Unit information / Compressor
Information.
Display the active alarms and to
perform alarm manual resets.
Scroll the various screens when the
cursor is in the top left of the display.
If the cursor is inside a numeric field,
the button increases or decreases
the corresponding value. If the field is
a selection, pressing the button
displays the available options.
To move the cursor around the
screens and to save the values of the
set parameters
Press down arrow key or press alarm
key to go to next screen for other alarm
history:
To clear alarm history, press input key
and authorization key together and then
press the alarm key again. Now the
display should be showing “No alarm”
ALARM HISTORY
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4.0 ELECTRICAL
4.3.3 AUTHORIZATION
4.3.3.1 Authorization key
To get authorization level, press
authorization key:
The display is showing the current
access level as view only:
PASSWORD= 0000
Status=View
Press enter key and use the up-down
arrow key to change the password
settings and press enter key to confirm.
Now the authorization status change to
different access level.
4.3.4 ADV ANCED USER KEY AND
MENU
4.3.4.1 User Key
User key is use to view and change the
pressure, ampere safety limits and
liquid injection temperature setpoints,
unit of measurements. In order to gain
access to this button, you must be
authorized and log in at least as user
level.
Press the user key and display is
showing the data as follows:
Press down arrow key or user key to go
to next screen for other setpoint:
To alter setpoint data, press enter key
to select the setpoint to alter and use
the up-down arrow key to change the
value and press enter key to confirm.
Repeat the above steps for others
setpoints.
4.3.5 TECHNICIAN KEY AND MENU
4.3.5.1 Technician status key
This key is use to view and change the
compressor FLA setpoint, sensors
calibration, manually control digital
inputs and outputs, manually control
compressor. In order to gain access to
this button, you must be authorized and
log in at least as user level. See the
authorization section about this
procedure.
4.3.5.2 Technician status key –main
menu
Press technician key to go to technician
setpoints main menu:
The display is showing the data as
follows:
Comp FLA Calibration
Sensor Calibration
Manual Control
Compressor Control
Sensors Override
Press enter key to move the cursor to
the sub-menu.
Technician Setpoints
Main Menu
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4.0 ELECTRICAL
The display is showing the data as
follows:
Comp FLA Calibration ■
Sensor Calibration
Manual Control
Compressor Control
Sensors Override
4.3.5.3 Compressor FLA Calibration:
To calibrate compressor FLA, press
down arrow key to go the sub-menu
'Comp FLA Calibration',
The display is showing the data as
follows:
Press enter key to move the cursor to
calibrate the comp FLA and use the updown arrow key to change the value
and press enter key to confirm.
4.3.5.4 To perform Sensor Calibration:
Press technician key to go to technician
setpoints main menu and press enter
key twice to move the cursor to the
sensor calibration sub-menu:
The display is showing the data as
follows:
Comp FLA Calibration
Sensor Calibration ■
Manual Control
Compressor Control
Sensors Override
Technician Setpoints
Main Menu
Technician Setpoint 1
Comp 1 FLA CALIBRATION
211x00.66+97.80
FLA = 237A
Capacity C1 = 000.0%
Min. Percent Cal = 25.0%
Max. Percent Cal = 00A
Technician Setpoints
Main Menu
Use up or down arrow key to move the
cursor to the desired 'Sensor
Calibration',
The display is showing the data as
follows:
Sensor Offset 1
Suction Press
Current = 076PSI [5.4BAR]
Average = 187PSI [8.6BAR]
24Hrs MAX = 200PSI [11.4BAR]
24Hrs MIN = 074PSI [4.6BAR]
Calibration = 00PSI [0.0BAR]
Press enter key to move the cursor to
calibrate the desired sensor and use
the up-down arrow key to change the
value and press enter key to confirm.
Repeat the above steps for others
sensors calibrations.
4.3.5.5 Manual Control:
A digital input sensor or relay output
can be controlled manually with the
keypad. Digital input sensor or relay
output can be turned on, off manually
and placed back to auto mode.
To place a digital input or relay output
in manual control, the operator must be
authorized at technician level or higher.
Press technician key to go to technician
setpoints main menu and press enter
key three times to move the cursor to
the manual control sub-menu:
The display is showing the data as
follows:
Comp FLA Calibration
Sensor Calibration
Manual Control ■
Compressor Control
Sensors Override
Technician Setpoints
Main Menu
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4.0 ELECTRICAL
Use up or down arrow key to move the
cursor to the desired digital input or
relay output,
The display is showing the data as
follows:
C1 Starter= Auto
C1 Oil Lvl= Auto
Unit Enable= Auto
Flow Switch= Auto
Press enter key to move the cursor to
the desired point for manual control and
use the up or down arrow key to
change the status of the digital input or
relay output to AUTO/CLOSE/OPEN or
AUTO/ON/OFF.
The display is showing the data as
follows:
Alarm Relay Auto
Liquid Inj C1 Auto
CW Pump Auto
Vap Inj Relay Auto
Press enter key to confirm the change.
4.3.5.6 Compressor Control:
Screw compressors can be controlled
manually with the keypad. A
compressor can be turned on, off, or
placed in computer control. When a
compressor is controlled manually, it
can be commanded to load, hold, or
unload. If safety limiting condition is
active, it will not accept a load
command.
To place a compressor in manual
control, the operator must be
authorized and log in as technician
level and higher.
Digital Inputs
Manual Control
Relay Outputs
Manual Control
Press technician key to go to technician
setpoints main menu and press enter
key four times to move the cursor to the
manual control sub-menu:
The display is showing the data as
follows:
Comp FLA Calibration
Sensor Calibration
Manual Control
Compressor Control ■
Sensors Override
Use down arrow key to move the cursor
to the desired compressor control
screen, then press enter key to move
the cursor to compressor status
position, AUTO /MAN/OFF
Use up or down arrow key to select
MAN and press enter key to confirm the
change. The compressor will start or
continue to run in hold state. Press the
user key to continue hold, press the
technician key to load and factory key
to unload.
Technician Setpoints
Main Menu
Compressor Control
Manual Override
Manual Hold Manual Load Manual Unload
If a safety condition is exceeded while
operating manually, the compressor will
shutdown.
CAUTION: Anti-recycle timer is
bypassed by manual control. DO NOT
start a compressor more than once
every 15 minutes.
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4.0 ELECTRICAL
NOTE: All compressors will revert back
to automatic control if the computer is
the computer is not given a load,
unload, or hold command at least once
every 15 minutes. A command can be
repeated to meet the 15 minute
requirement for manual control.
To the change the settings of
compressor load/Unload, follow the
above steps and go to compressor
control. Use down arrow key to move
the following and press to change the
settings.
Value of analog readings can be
temporary override during sensor
failure.
To override the analog readings, the
operator must be authorized at
technician level or higher.
Press technician key to go to technician
setpoints main menu and press enter
key five times to move the cursor to the
‘Sensors Override’ sub-menu:
The display is showing the data as
follows:
Comp FLA Calibration
Sensor Calibration
Manual Control
Compressor Control
Sensors Override
Use up or down arrow key to move the
cursor to the desired analog reading,
Load/Unload Control
Technician Setpoints
Main Menu
The display is showing the data as
follows:
Supply Water Temp
Man Reading = 45.0°F [7.2°C]
Manual Override = NO
Press enter key to move the cursor to
the “Man Reading” and use the up or
down arrow key to change the value of
the analog reading, press enter key
move the cursor to the “Manual
Override” to enable, or disable the
manual override control.
Sensors Manual
Override
Repeat the above steps for other
sensors override.
Caution: Sensors override require continuous
monitoring and observation by the field service
personnel at all time during the unit operation.
Faulty sensor shall be replaced as soon as
possible in order to allow the unit to be running in
automatic mode.
4.3.6 CONTROL FUNCTIONS
4.3.6.1 Chilled Water Pump Interlock
And Flow Switch (CWP And
CWFS)
These are field installed switches, both
of which are used to ensure chilled
water flow before the unit is allowed to
start. Failure of either one during
operation will cause the compressor to
shut down.
A water flow alarm will be generated
and ‘Rest Alarm’ must be pressed to
clear the alarm.
4.3.6.2 Customer Control Interlock
Control contacts from an external
controller can be used to enable or
disable operation of the unit. The wiring
diagram specifies the terminals to
which the contacts must be wired. To
enable the unit, the contacts must be
closed. To disable the unit, the contacts
must be opened.
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4.0 ELECTRICAL
4.3.6.3 Anti-Recycle Timer
The compressor motor requires an antirecycle time delay which prevents
restart for 15 minutes after a start. The
purpose of this feature is to avoid
frequent starts which tend to elevate
the motor winding temperature and
impose undue wear on contactors. The
controller will not restart the
compressor motor until the 15 minutes
have elapsed.
4.3.6.4 Load Control
The controller controls the leaving
water temperature within a narrow
deadband by pulsing load and/ or
unload solenoids on the compressor.
The load and unload solenoids position
the slide valve within the compressor to
control its capacity. The controller
determines a desired level of loading
and varies pulse duration depending on
difference between load target and
actual load. The load target is varied
based on rate of approach to desired
temperature preventing significant
temperature oscillations. The status of
the compressor can be observed by
displaying the compressor control point.
4.3.6.5 Ramp Control
Another feature of the controller is ramp
control, which is the ability to vary load
time of the machine from start. Often
when the machine is started, the water
in the chilled water circuit is warm, and
the unit will go to full load quickly. With
ramp control, the user can program the
computer so that it loads at a
predetermined rate. This is a valuable
tool, since it can help reduce power
consumption and demand charges.
Two variables are used to define the
ramp profile: Ramp rate and start point.
Ramp rate defines the length of time
the unit takes to load from start point to
full load. Start point is the percent of full
load at which the ramp begins. The
ramp rate A setpoint can be set
anywhere from 0.1 to 1.0, smaller
values producing slower loading rates.
The ramp start B setpoint can be set
anywhere between 0 and 50%. The
compressor will load quickly to this
value and then follow the ramp slope
from there. See Table 4.3.6.5 for ramp
rates at various settings.
4.3.6.6 Staging Control
On multiple-compressor machines,
when the controller determines that a
compressor is fully loaded and
temperature is not being maintained,
another compressor is added. When
unloading, a compressor is taken off
line when the computer determines that
the remaining compressors can control
water temperature.
4.3.6.7 Pumpdown Control
This feature is to stored refrigerant in
condenser when compressor is
stopped. Pumpdown control will take
place when temperature set point is
achieved before compressor is being
cycled off or unit enable input is off.
The compressor will stop when suction
pressure is lower than pumpdown
setpoint, 65PSI [4.5BAR] (for R22) or
15 seconds (setpoint) delay timer is
elapsed.
TABLE 4.3.6.5 Ramp Rates for Several Setpoints (In Minutes)
When compressors starts, the liquid
line solenoid will energize when suction
pressure falls below the pumpout
setpoint or a time delay of 5 seconds is
elapsed. For unit with two liquid lines
per refrigerant circuit, the second liquid
line solenoid will energize when suction
pressure falls below low pressure
cutout setpoint or a time delay of 25
seconds is elapsed and unit target is
above 40%. The second liquid line
solenoid will be de-energized when the
unit target is less than 35%.
4.3.6.9 Sump Heater Control
Each compressor is fitted with an oil
sump band-heater. The heater is
energized at all times when compressor
is off and de-energized when the
compressor is running.
Its purpose is to prevent refrigerant
migration into the oil during shut down.
For this reason, it is essential that
heaters be energized for 24 hours
before starting a compressor.
4.3.6.10 Low Pressure Cut-off
This function protects the unit from
operating at abnormally low evaporator
refrigerant pressure. The controller will
shut down the compressor when
evaporator pressure falls below the low
pressure setpoint and turn on the alarm
pilot light.
A low pressure alarm will be recorded
by the controller. Reset by pressing the
‘Reset Alarm’ button on the controller.
Standard setpoint is 58 psig [4.0BAR].
4.3.6.11 Evaporator Freeze Shutoff
If the leaving chilled water temperature
drops below the freeze setpoint, the
controller will shut down the unit and
store the freeze alarm. After solving the
problem, press ‘Reset Alarm’ on the
controller to clear the alarm.
4.3.6.12 High Pressure Cut-off
This function protects the compressor
from operating at abnormally high
discharge refrigerant pressures. The
controller will shut down the
compressor when condenser pressure
reaches the high pressure set point,
and turn on the alarm indicator lamp on
the control box. The high discharge
pressure alarm will be recorded by the
controller. Reset by pressing the ‘Reset
Alarm’ button on the controller. Setpoint
is 400 psig [27.6BAR].
4.3.6.13 Phase Control Relay (PCR)
- Optional
The PCR protects the unit from the
following electric supply malfunctions:
Undervoltage, phase reversal and
single phasing. If the PCR trips, a
control relay (lCR) will de-energize and
open the control circuit. A green LED
indicates presence of power supply.
The yellow LED indicates a good
voltage supply. The power loss setpoint
is factory set to AUTO to allow
automatic start after PCR failure.
Compressor will not start for 15 minutes
after failure. To select manual reset, set
power loss setpoint to MANUAL. In this
case, a power loss alarm will be stored
by the controller and ‘Reset Alarm’
must be pressed to start.
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4.0 ELECTRICAL
4.3.6.14 Sensor Alarm
If the computer measures an analog
value (temperature, pressure.) that is
far beyond normal operating values, the
associated compressors are shutdown.
The computer then stores the alarm
code corresponding to the sensor
alarm. A sensor alarm indicates a
problem in the analog measurement
system.
4.3.6.15 No-Stop Alarm
If the controller turns off a compressor,
but the compressor digital input does
not turn off, a No-Stop alarm is
generated. The computer will turn off
the control power relay which disables
all compressor control circuits and will
turn on the alarm light. This alarm
indicates a wiring or hardware error.
4.3.6.16 Low Differential Pressure Alarm
For proper lubrication, a compressor
requires a 30 psid [2.1BAR] differential
pressure between condenser and
evaporator pressures. If the differential
pressure is less than 30 psid [2.1BAR]
for 3 minutes while a compressor is
operating, all compressors will be shut
down. The controller will store the low
differential pressure alarm code and
turn on the alarm light. The ‘Reset
Alarm’ key must be pressed to clear the
alarm.
4.4 CONDENSER FAN
CONTROL LOGIC
If the differential pressure is less, the controller
provides two types of control logic for air-cooled
condensers. The type of control will be governed
by the physical condenser layout of the unit. Each
method of control is enhanced with adaptive, selflearning, fan control logic. The end result is
condenser control that offers significantly reduced
fan cycling and improved efficiency. The two
types of air-cooled condenser control logic are
explained as follows:
1. Adaptive Individual Air-cooled Condenser
Control
This type of control is based upon a single
compressor per circuit. The individual
discharge pressure on that circuit will be the
controlling pressure.
2. Adaptive Air Combined Air-cooled
Condenser Control
This type of control is based upon a condenser
that is controlled by the highest discharge
pressure from any one of the compressors
sharing that circuit (compressor 1&2 - share;
compressor 3&4 - share). The highest
discharge pressure between the sharing
compressors will be the controlling pressure.
4.4.1 Air Cooled Condenser Control
Setpoints
The air-cooled condenser setpoints are as
follows:
Setpoint COND Stage 1 ON - Condenser stage
1 on.
Setpoint COND Stage 2 OFF - Condenser stage
2 off.
Setpoint COND DIFF ON - Differential
pressure for
additional
condenser stages.
Setpoint COND DIFF OFF - Differential
pressure for
subtracting
condenser stages.
A compressor must be operating for the
condenser fans to operate. The condenser points
(i.e. fans) will turn on based upon the value in
setpoint COND Stage 1 ON. When the discharge
pressure exceeds this value, the first condenser
point is turned on. If additional condenser points
exist, they will be turned on when the pressure
exceeds the previous cut in value (COND Stage 1
ON for the first stage) plus the value contained in
COND DIFF ON setpoint.
Condenser points (i.e. fans) will be turned off
based upon the value in the setpoint COND ST2
OFF (COND Stage 2 turn OFF point). As the
discharge pressure is reduced, the condenser
points will be turned off based upon the COND
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4.0 ELECTRICAL
ST2 OFF setpoint, plus the value in the COND
DIFF OFF setpoint for each stage number above
stage 2. Stage 2 of condenser staging will be
turned off based upon the value in the setpoint
(COND ST2 OFF). See below for an example of
condenser staging.
4.4.2 INCREASING CONDENSER
PRESSURE
(Example of 4 stage fan cycling)
COND FAN1 ON when discharge pressure is >
230psig [15.9BAR] (COND Stage 1 ON setpoint)
COND FAN2 ON when discharge pressure is >
250psig [17.2BAR] (COND Stage 1 ON plus
1xCOND DIFF ON setpoint values)
COND FAN3 ON when discharge pressure is >
270psig [18.6BAR] (COND Stage 1 ON plus
2xCOND DIFF ON setpoint values)
COND FAN4 ON when discharge pressure is >
290psig [20.0BAR] (COND Stage 1 ON plus
3xCOND DIFF ON setpoint values)
And so on for the number of condenser fans
supplying the circuit.
4.4.3 DECREASING CONDENSER
PRESSURE
(4 fan example "continued")
COND FAN4 OFF when discharge pressure
is < 200psig [13.8BAR] (COND Stage 2 OFF plus
2xCOND DIFF OFF setpoint values)
COND FAN3 OFF when discharge pressure
is < 190psig [13.1BAR] (COND Stage 2 OFF plus
1xCOND DIFF OFF setpoint values)
COND FAN2 OFF when discharge pressure
is < 180psig [12.4BAR] (COND Stage 2 OFF
setpoint value)
COND FAN1 OFF when discharge pressure
is < 170psig [11.7BAR] (COND Stage 1 OFF
setpoint value)
4.4.3.1 Adaptive Control Logic
The controller enhances the condenser
control logic above with a unique,
adaptive, self-learning fan control logic.
These enhancement results in a control
scheme that offers reduced fan cycling
and improved efficiency. Adaptive
Control Logic automatically adjusts the
fan cut-in offset based upon the
following criteria:
1. If the last fan turned on (including
FAN 1) is cycled off in 10 minutes
or less, then a COND ON OFFSET
value will be incremented by 5 psig
[0.3BAR]. This increases the fan 1
turn on value (COND ST1 ON plus
COND ON OFFSET) which in turn
increases all of the fan turn on
settings. This process will continue
until fan cycling ceases or the
adjusted turn on point for the last
fan stage is 320 psig [22.1BAR].
This will also be a setpoint.
2. The cut-in offset (COND ON
OFFSET) will be decreased by 5
psig [0.3BAR] if the last fan to be
turned on has not cycled off within
1 hour. The offset will continue to
decrease by 5 psig [0.3BAR] every
10 minutes unless fan cycling
begins again.
The Adaptive Control Logic will only
affect the condenser fan turn on logic, it
will not affect the fan turn off logic.
4.5 Master/Slave Control
Sequence
The optional master/slave control sequence is
used to sequence multiple chillers in one
installation according to the building load demand.
It also controls the dedicated chilled water pump
or motorized valve.
Vision2020i Controller offers this feature with
minimized field wiring cost compare to
conventional method that involves lots of
hardware cost. It is carried out this control
function via the advanced DBLAN communication
bus to implement the network management for
multiple chillers lead/lag communication,
sequencing and monitoring.
- 48 -
4.0 ELECTRICAL
4.5.1 PRINCIPL E OF OPERATION VIA DBLAN COMMUNICATION BUS
Example: 6 chillers network with 4 units on duty and 2 units standby
Graphic
Display
(option)
DBLAN
DBG1 DBG1 DBG1 DBG1
DB3 DB3 DB3
DB3
DBG1
DB3
DB3
DBG1
DB1
DB1
DB1
DB1 DB1
DB1DB1
DB1
DB1
DB1
DB1
DB1
#1 #2 #3 #4 #5 #6
Notes
a) Each chiller has a stand-alone master DB3 board and dedicated graphic display with multiple DB1
expanders board connected to J23 on DB3
b) Each chiller DB3 will be connected to DBLAN network through J11 connector
c) The chiller lead/lag selection can be determined by
D Manual lead/lag setpoint
D Schedule and holiday setup
D Alarm conditions
d) The lead/lag selection determine the chiller operation sequence as follows,
Lead chiller
selection
Normal chillers operation sequence When DBLAN fails
1 1, 2 & 3 on duty, 4, 5 & 6 standby 1, 2 & 3 on duty
2 2, 3 & 4 on duty, 5, 6 & 1 standby 2, 3 & 4 on duty
3 3, 4 & 5 on duty, 6, 1 & 2 standby 3, 4 & 5 on duty
4 4, 5 & 6 on duty, 1, 2 & 3 standby 4, 5 & 6 on duty
5 5, 6 & 1 on duty, 2, 3 & 4 standby 5, 6 & 1 on duty
6 6, 1 & 2 on duty, 3, 4 & 5 standby 6, 1 & 2 on duty
e) If the lead/lag selection is changed over to a different chiller, the sequence of operation will be
rotated
f) Each chiller will use a network address setpoint to determine individual chiller network address
g) Each chiller will require a dedicated chilled water pump or motorized valve digital output, unit enable
and chilled flow status digital inputs as well as enable next output command.
- 49 -
4.0 ELECTRICAL
4.5.2 Sequence Of Operation
1. When the customer enable input is ‘on’ to
start the lead unit, the chilled water pump
starter or motorized valve control point will
close and water will start to flow through the
evaporator, this will activate the flow switch.
The flow switch and water pump status are
interlocked and feedback as digital input to
the chiller and upon receipt of a valid 'on'
signal, the lead chiller will begin to execute its
running program.
a) LWT ≥ (LWT Setpoint + Enable Next
deadband)
b) After a enable next time delay of 3
minutes (adjustable) and
c) When the lead unit’s packaged capacity
is higher than “Next on setpoint”,
for example, WCFX2, %FLCP C1 & %FLCP C2 ≥
Next on setpoint
or it is being lockout by an alarm.
2. The controller will start and load the
compressor(s), upon achieving full load; it will
send an output signal via the DBLAN to
enable second unit (lag 1)
3. The second unit will now command its chilled
water pump to start if the customer unit
enable is activated. The second chiller will
start and load the compressor(s) until it
reaches full load
4. When the second chiller or lag 1 unit reaches
full load, it will enable the third chiller.
5. The chiller will keep cascading until all chillers
on duty are at full load.
6. If the leaving water temperature falls below
setpoint, all of the chillers will begin to unload
evenly.
7. If the load drops below 45% total capacity,
delay the last unit (lag 3) will be disabled, and
the remaining three units will load up to
compensate if necessary. The pump for
chiller 4 will be shut off.
4.6 VISION 2020i LOCAL AREA
NETWORK (DBLAN)
A DBLAN network is made up of several chillers’
controller. Each unit’s controller can be
programmed and connected to the local DBLAN
network that allows multiple units sequencing
control without additional hardware.
Every DBLAN node must be addressed to be
identified by the other nodes. Each address (an
integer number) must be unique in the network for
avoiding messages mismatch: in case two or
more nodes have the same identifying address
the network cannot work.
The max address number selectable is in the 1-16
for the Vision 2020i controller boards and 17-32
range for the Vision 2020i User terminal.
The three chiller unit combinations:
8. As the load demand falls, the lag 2 unit will be
disabled below 45% total capacity, and so on
until the load falls enough to shut off the lead
chiller.
9. Each unit in the network can monitor the
operation of other units via DBLAN. If the
master unit is having critical alarm, the lag 1
will take over as the master unit automatically.
10. In order to enable next unit, the following
conditions must met
Controller with address of 1 connect to Terminal
with address of 17
Controller with address of 2 connect to Terminal
with address of 18
Controller with address of 3 connect to Terminal
with address of 19
Follow the following steps:
- 50 -
4.0 ELECTRICAL
4.7 NETWORK CONNECTION DIAGRAM
Adr:17 Adr:18 Adr:19
Telephone Cable Telephone Cable Telephone Cable
J10 Adr:1 J10 Adr:2 J10 Adr:3
RS 485 Cable RS 485 Cable
max 500 meters max 500 meters
Vision 2020i
Terminal
Vision 2020i
Controller
J11 J11 J11
Vision 2020i
Terminal
Vision 2020i
Controller
Vision 2020i
Vision 2020i
Terminal
Controller
The 6 core telephone cables (to J10 socket) are supply by the manufacturer.
The 3 core RS 485 data cables (to J11 socket) are supply by the customer.
Pay attention to the network polarity:
RX+/TX+ on one controller must be connected to RX+/TX+ on the other controller; the same is true for
RX-/TX- and GND.
4.8 HARDWARE SETTINGS
4.8.1 ADDRESSING THE VISION 2020i
CONTROLLER
At the Vision 2020i terminal, push simultaneously
the last three keys on the lower right corner of the
Vision 2020i terminal keyboard. Push them for at
least 5 seconds.
This display will appear:
5 sec
Display address
Setting……… : 17
I/O Board address: 01
Vision 2020i
Change the display address setting to 0 as follow.
Turn off DB3 controller.
At the Vision 2020i DBG1 terminal, hold
simultaneously the “Alarm” key and “Up arrow”
key, turn on DB3 controller and hold these keys
until “Self Test” mask is appeared.
Display address
Setting……… : 0
Vision 2020i
- 51 -
4.0 ELECTRICAL
The following mask will appear. Set pLAN
address to 1 (or accordingly) using “Up” and
“Down” arrow key. Press “Enter” key to save and
exit.
The terminal display will become blank after
“Enter” key is pressed. Please proceed to next
section on Addressing the Vision 2020i DBG1
Terminal.
4.8.2 ADDRES S ING THE VISION
At the Vision 2020i DBG1 terminal, hold
simultaneously the last three keys on the lower
right corner of the Vision 2020i terminal keyboard.
Hold them for at least 5 seconds.
The display will appears:
The first line is the address of the terminal display
that you are using, (for first chiller, it is 17). The
next line allows you to select the Vision 2020i
controller address (for first chiller, it is 01) that you
***********************************
SELF TEST
PLEASE WAIT
************************************
PLAN Address : 1
Up : Increase
Down : Decrease
Enter : Save & Exit
2020I DBG1 TERMINAL
5 sec
Display address
Setting……… : 17
I/o Board address: 01
Vision 2020i
want to configure. Once you select the address
then press ‘enter’ button
The display will appears:
Push ‘enter’ to continue.
Then the display appears:
Set Trm1, Trm2 and Trm3 to ’17 Pr’,’32 Sh’ and
‘None ---’, change the 'NO' to 'YES'(to confirm
and save) and press ‘enter’.
Note: Pr = Private, Sh = Share.
For multiple units with master-slave sequencing
control features, at the second chiller unit Vision
2020i terminal; repeat step 1 by holding the three
keys again. The display will appears:
The address display (18) is the correct setup for
the second chiller unit with the controller address
of two (P:02).Press ‘enter’ to confirm the settings
and the display will appears:
P:01 Adr Priv/Shared
Trm1 17 Pr
Trm2 32 Sh
Trm 3 None --- OK? NO
Display address
Setting……… : 18
I/o Board address: 02
Terminal config
Press ENTER
To continue
Terminal config
Press ENTER
To continue
- 52 -
4.0 ELECTRICAL
Set Trm1, Trm2 and Trm3 to ’18 Pr’,’32 Sh’ and
‘None ---’, change the 'NO' to 'YES'(to confirm
and save) and press enter.
P:02 Adr Priv/Shared
Trm1 18 Pr
Trm2 32 Sh
Trm 3 None --- OK? NO
At the third chiller unit Vision 2020i terminal:
Press the three keys again, the display will
appears:
Display address
Setting……… : 19
I/o Board address: 03
The address display (19) is the correct setup for
the third chiller unit with the controller address of
three(P:03).Press ‘enter’ to confirm the setting
and the display will appears:
Terminal config
Press ENTER
To continue
Table 4.8.3 LED Status
LED STATUS DESCRIPTION
Set Trm1, Trm2 and Trm3 to ’19 Pr’,’32 Sh’ and
‘None ---’, change the 'NO' to 'YES'(to confirm
and save) and press enter.
P:02 Adr Priv/Shared
Trm1 19 Pr
Trm2 32 Sh
Trm 3 None --- OK? NO
With the above settings, terminal with address 17
will only work with the controller with address 1,
terminal 18 will only work with the controller with
address 2, terminal 19 will only work with the
controller with address 3 and a terminal with
address 32 will work with both.
4.8.3 Vision 2020i Controller LED
Status
Vision 2020i controller have three LEDs between
the J3 and J4 connectors for indicating basic
node status. They are Red, Yellow and Green
coloured.
Red Yellow Green
At the start-up all LEDs are ON and after few
seconds OFF again. After 5 – 15 seconds elapse,
then LED configuration is among those listed
below.
GREEN
YELLOW
RED
ON
OFF Vision 2020i controller is not network connected or it doesn’t receive any signal from the DBLAN
BLINKING Vision 2020i controller is transmitting data to other network nodes.
OFF Vision 2020i controller is not transmitting messages.
OFF No hardware and software problem.
ON
BLINKING
Vision 2020i controller is synchronized with all the other DBLAN nodes.
The node is working correctly.
Vision 2020i controller software not compatible or variables database not correct, contact DunhamBush Service Personnel.
Vision 2020i hardware is not compatible - Ram is smaller than 32 KB.
The Vision 2020i controller is just for working in stand-alone mode.
- 53 -
4.0 ELECTRICAL
4.9 TYPICAL WIRING SCHEMATIC
ACDS 010
- 54 -
4.0 ELECTRICAL
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4.0 ELECTRICAL
ACDS 020
- 56 -
4.0 ELECTRICAL
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ACDS 030
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4.0 ELECTRICAL
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4.0 ELECTRICAL
ACDS 040
- 60 -
4.0 ELECTRICAL
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4.0 ELECTRICAL
ACDS 050, 060, 070
- 62 -
4.0 ELECTRICAL
- 63 -
4.0 ELECTRICAL
ACDS 080, 90
∼∼∼
∼∼∼
- 64 -
4.0 ELECTRICAL
∼
∼∼
∼
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4.0 ELECTRICAL
∼∼
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4.0 ELECTRICAL
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4.0 ELECTRICAL
ACDS 100
∼∼∼
∼∼∼
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4.0 ELECTRICAL
∼
∼∼
∼
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4.0 ELECTRICAL
∼∼
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4.0 ELECTRICAL
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ACDS 120
∼∼∼
∼∼∼
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4.0 ELECTRICAL
∼
∼∼
∼
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4.0 ELECTRICAL
∼∼
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4.0 ELECTRICAL
ACDS 135
∼∼∼
∼∼∼
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4.0 ELECTRICAL
∼
∼∼
∼
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∼∼
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4.0 ELECTRICAL
ACDS 150
∼∼∼
∼∼∼
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∼
∼∼
∼
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∼∼
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ACDS 165, 180
∼∼∼
∼∼∼
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∼
∼∼
∼
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∼∼
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4.0 ELECTRICAL
- 87 -
5.0 MAINTENANCE
5.1 GENERAL
As with all mechanical equipment, a program of
regular inspection, cleaning and preventive
maintenance by trained personnel will contribute
greatly to the long satisfactory service life of this
product.
5.2 PERIODIC INSPECTION
Read essential temperatures and pressures
periodically to see that they indicate normal
operation. It is a good idea to record these
readings on a log sheet. If any abnormal
operation is observed, try to remedy it. See
Trouble Shooting Guide Section.
5.3 MONTHLY INSPECTION
Check cooling tower water treatment system,
Wipe down external surfaces of unit. Shut unit
down, open main disconnect, inspect control
panel, checking for loose wires, burned contacts,
signs of overheated wires, etc. Restart unit and
check performance of controls. Check sight
glasses for proper refrigerant charge.
5.4 PHE MAINTENANCE
5.4.1 GENERAL
The efficient performance of the
evaporator and condenser heat transfer
surfaces is essential for efficient
performance of your packaged water
cooling machine. If these surfaces
accumulate a film of dirt, scale or slime,
their performance efficiency will degrade
substantially. The refrigerant side of heat
transfer surfaces does not foul since
refrigerant is a good solvent and it is in a
closed, filtered cycle. Water side surfaces
can foul from the water system. A
program of water treatment can slow the
rate of fouling on heat transfer surfaces,
but not eliminate it.
5.4.1.1 Freezing Protection For BPHE
a.) Use a filter <1mm, 16 mesh (see
previous chapter on BPHE
maintenance)
b.) Use an anti-freeze when the
evaporation temperature is close to
liquid-side freezing
c.) Use a freeze protection thermostat
and flow switch to guarantee a
constant water flow before, during
and after compressor operation.
d.) Avoid "pump-down" function
e.) When starting up a system, wait a
moment before starting the
condenser (or have reduced flow
through it)
5.4.2 EVAPORATOR CLEANING
5.4.2.1. Cleaning BPHE
Normally very high degree of
turbulence in BPHE there is a selfcleaning effect in the channels.
However, in some applications the
fouling tendency can be very high.
In such cases, it is always possible to
clean the exchanger by circulating a
cleaning liquid (CIP-Cleaning In Place).
Use a tank with weak acid or, if the
exchanger is frequently cleaned, 5%
oxalic acid.
Pump the cleaning through the
exchanger.
For optimum cleaning, the cleaning
solution flow rate should be a minimum
of 1.5times the normal flow rate,
preferably in a back-flush mode.
After use, do not forget to rinse the heat
exchanger carefully with clean water.
A solution of 1-2% sodium hydroxide
(NaOH) or sodium bicarbonate
(NaHCO₂) before the last rinse ensure
that all acid is neutralized. Clean at
regular intervals.
- 88 -
5.0 MAINTENANCE
5.4.2.2. Strainers
If any of the media contains particle
larger 1mm (0.04 inch), we recommend
that a strainer with a size of 16-20
mesh (number of openings pe inch) is
installed before the exchanger.
The particles could otherwise block the
channels, causing bad performance,
increased pressure drop and risk of
freezing.
5.5 AIR COOLED CONDENSER
CLEANING
The face of the condenser should be cleaned at
least once month during operation. If conditions
are bad and condensers pick up dirt very quickly,
it is suggested that they can be cleaned more
frequently.
If the condenser is allowed to get too dirty, the
unit will run at high head pressure and will not
give satisfactory performance.
Dirty coils can be cleaned using a soft brush or by
flushing with cool water or commercially available
coil cleaners.
DO NOT USE HOT WATER OR STEAM. To do
so will cause excessive pressure in the system.
The face of the condenser should be cleaned at
the beginning of the season and periodically
thereafter if conditions require.
5.6 ELECTRICAL
MALFUNCTION
The unit has four devices designed to protect
compressor motors and manual motor controllers
from electrical malfunctions: Circuit breakers.
starter overload relays, under voltage relay
(optional), and motor over temperature protectors.
If the under voltage relay trips, it is a sign of
trouble in incoming power. If it trips again after
resetting, call your electric utility to investigate the
problem. If circuit breaker or motor overload relay
or motor over temperature protectors trip, this is a
sign of possible motor trouble. DO NOT reset and
try to run compressor again. Call authorized
service representative to check for motor trouble.
Resetting these safety devices and repeated
starting could turn a minor motor problem into a
costly major motor burnout.
5.7 REFRIGERANT CHARGE
5.7.1 GENERAL
All packaged chiller units are given a
complete charge of refrigerant at the
factory. The type and amount of
refrigerant required is in Physical
Specifications. The total refrigerant
shown is for the entire system. Since
these units have separate circuits, each
circuit should be considered separately
for charging.
In order to check proper refrigerant
charge, look in each liquid line sight glass
with the aid of a flashlight during system
operation. At all operating conditions, the
sight glass should be clear. If bubbles are
visible at any operating condition, the
circuit is short of charge.
Be careful not to overcharge the machine.
overcharging will result in considerable
liquid logging in the condenser, and
excessive condensing pressure.
To add refrigerant, connect a refrigerant
vessel to the 1/4" [6.4mm] back seating
port of the suction valve. Purge the air
from the tube with refrigerant gas before
connecting. With the unit running, open
the refrigerant vessel vapor connection
slightly. If the refrigerant vessel is warmer
than the evaporator, refrigerant will more
readily flow from the vessel into the unit.
5.7.2 AIR COOLED PACKAGES
To determine the proper refrigerant
charge, check the amount of subcooling if
possible. The amount of subcooling at the
liquid line (liquid line saturation
temperature corresponding to liquid line
pressure minus liquid line temperature)
should be between 15°F [8.3°C] and 20°F
[11.1°C]. Subcooling at the condenser
out-subcooler inlet trap should not exceed
5°F [2.8°C]. This sight glass should be
clear with no bubbles.
- 89 -
5.0 MAINTENANCE
TABLE 5.4 R410A PRESSURE/ TEMPERATURE PROPERTIES
Pressure Temperature Pressure Temperature Pressure Temperature Pressure Temperature
psig kPa °F °C psig kPa °F °C psig kPa °F °C psig kPa °F °C
5. Check pump fuses, starter heater elements,
pressure and temperature controls.
1. Check at main entrance and at unit. Consult power
company if voltage is low and increase wire size to
the unit if voltage is normal at main and low at unit.
Voltage must be within 10% of motor nameplate
rating.
2. Check fuses and wiring.
3. Check the contacts and time delay on part wind
start.
1. Check for leaks and add refrigerant.
2. Check pump operation and water flow.
3. a.) Plugged drier. If temperature drop exists across
the drier remove and replace cores.
b.) Liquid line or suction valve partially closed. Open
valves fully and close in one full turn.
c.) Expansion valve clogged or inoperative. Check
superheat setting. Check charge and thermo
bulb.
4. Restrict water flow to condenser by adjusting the
water regulating valve or cycle cooling tower fan.
4. Compressor
cycles on
high
pressure
control
1. Compressor discharge
valve partially closed.
2. Air in system
3. Overcharge of
refrigerant
4. High pressure control
improperly set
5. Main water valve closed
6. Water regulating valve
set high or defective
7. Condenser fan
inoperative
8. Dirty condenser
9. Fan cycle switches inoperative, or set too
high
10. Fan motors not running
11. Fan motor reverse
rotation
1. Open valve fully and close with one turn
2. Flush water valve. If pressure in system exceeds the
pressure corresponding to the water temperature
purge air from compressor gauge connection.
3. Purge system while in operation until bubbles show
in sight glass. Close valve and add small amount of
refrigerant until sight glass just clears.
4. Adjust the control.
5. Open the water valve.
6. Reset or replace valve.
7. Check, replace or repair set screw (pulley), fan
motor, or inoperative fan control.
8. Clean condenser surfaces with brush and/or
vacuum.
UNIT MODEL NO. ........................................................ UNIT NO. .................................... VOLTS: ............................ Hz ..................
UNIT SERIAL NO. ........................................................ COMPRESSOR MODEL NOS. ....................................................................
START UP : DATE .......................................... TIME ....................................................
DATE
TIME
ELAPSED TIM E METERS
COMP. NO.
SUCTION
PRESSURE
DISCHARGE
PRESSURE
DISCHARGE
TEMPERATURE
DISCHARGE SUPERHEAT
(DISC. TEMP.-SAT. DISCH.)*
DISCHARGE SUPERHEAT
(DISC. TEMP.-SAT. SUCT.)*
EVAPORATOR WATER TEMPERATURE-IN
EVAPORATOR WATER TEMPERATURE-OUT
EVAPORATOR PRESSURE DROP ftwg[kPa]
EVAPORATOR WATER FLOW gpm [m³/hr]
CONDENSER AIR TEMPERATURE-IN
(AMBIENT) AC ONLY
ACTUAL VOLTAG E
COMPRESSOR AMPS
FAN AMPS
VOLTS
*USE TABLE 5.4 FOR OBTAINING SATURATED TEMPERATURE
THIS LOG SHEET IS PROVIDED AS A RECOMMENDATION OF THE READINGS THAT SHOULD BE TAKEN ON A PERIODIC BASIS. THE
ACTUAL READINGS TAKEN AND THE FREQUENCY WILL DEPEND UPON THE UNITS APPLICATION, HOURS OF USE, ETC. THIS TYPE OF
INFORMATION CAN PROVE VERY USEFUL IN PREVENTING AND/ OR SOLVING PROBLEMS THAT MIGHT OCCUR DURING THE LIFE OF
THE UNIT.
1.
2.
3.
4.
1.
2.
3.
4.
1.
2.
3.
4.
1.
2.
3.
4.
1.
2.
3.
4.
1.
2.
3.
4.
- 92 -
Products that perform...By people who care
Corporate Head Office
DUNHAM-BUSH HOLDING BHD
(Formerly known as Dunham-Bush (Malaysia) Bhd) (129358-X)
Manufacturer reserves the right to change specifications without prior notice.
Lot 5755-6, Kidamai Industrial Park, Bukit Angkat
43000 Kajang, Selangor Darul Ehsan, Malaysia.
Tel: 603-8733 9898 Fax: 603-8739 5020
E-Mail: info@dunham-bush.com.my
www.dunham-bush.com
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