Unitrol PROCESS 8500 User manual

PROCESS WATER CHILLER
MODELS 8500, 8501, 8550, 8551
UNITROL ELECTRONICS, INC.
702 LANDWEHR ROAD
NORTHBROOK, IL 60062
847-480-0115
[e-mail]
Shown with option #8510 stacking stand.

WARRANTY
PARTS: Unitrol warrants this chiller to be free of defects in materials that
effect operation, for a period of one year from date of shipment from
factory, if said equipment has not been altered or abused by customer
and is being used for the purpose that the equipment was designed for.
Parts will be shipped, FOB Northbrook, Illinois. Defective parts will be
returned to Unitrol at customer’s expense when so requested by Unitrol.
LABOR: Necessary warranty labor is covered for a period of 90 days
from the date of shipment from factory, if said equipment has not been
altered or abused by customer and is being used for the purpose that
the equipment was designed for. Parts will be replaced or repaired, at
manufacturer’s option on any parts found to be defective. Unitrol shall
not, without its prior written approval, be liable for any costs involved in
field repairs. Transportation of equipment to or returning from Unitrol
shall be at customer’s expense.
Alternately, Unitrol may elect to send a local refrigeration contractor to
do warranty service. In this case, Unitrol will pay contractor directly.
To be covered by this warranty, please follow the following procedure:
1. Contact the Unitrol service department at 847-480-0115 to discuss
the problem you are having with this chiller.
2. If Unitrol concurs that this is a warranty issue, and the chiller is
more than 90 days from date of factory shipment, a Unitrol
representative will either arrange to have a replacement part
shipped, or authorize a locally purchased replacement at a pre-
agreed price that will be reimbursed by Unitrol.
3. If Unitrol concurs that this is a warranty issue, and the chiller is
less than 90 days from date of factory shipment, a Unitrol
representative will have a factory approved service technician
dispatched to make repairs under the above terms. Alternately, the
Unitrol representative will direct that the chiller be returned to the
factory for repairs.
No other warranty, either written or implied, shall cover this equipment,
and Unitrol shall not be liable for any damage caused to other equipment
or personnel due to failure of this product. Unitrol reserves the right to
change specifications at any time.

UNITROL PROCESS WATER CHILLER
Thank you for purchasing this Unitrol process water chiller. It was manufactured
with pride in our Northbrook, Illinois factory. Unitrol also manufactures the Unitrol
line of RESISTANCE WELDING CONTROLS. This line includes controls that
include safety systems to protect the welding machine operator, as well as quality
control features that allow you to produce a large volume of weldments that will
match the highest quality requirements.
This Unitrol water chiller has been designed to operate under the most severe
industrial conditions. Please observe the installation instructions to be sure that
this chiller will provide years of superior service.
MODEL NUMBER:
SERIAL NUMBER:
DATE OF MANUFACTURE:
REFRIGERANT: 407C
4400000
OPTIONS:
CHILLER MODEL
LINE
VOLTAGE
AND PHASE
STANDARD
WATER PUMP
8500 / 25 tons
480/3
5 HP, 180GPM @35PSI
8501 / 25 tons
230/3
5 HP, 180GPM @35PSI
8550 / 30 tons
480/3
7-1/2HP, 230GPM @35PSI
8551 / 30 tons
230/3
7-1/2 HP, 230GPM 35PSI
This model chiller is supplied in three MODULES:
MODULE A = Main module with water pump, compressor 1, and control panel
MODULE B = Remote module with water tank and compressor 2
MODULE C = Remote module with compressor 3
Field connection of electrical and water circuits is required. All wires and hosing is
provided for this interconnection.
INCLUDED IN SHIPMENT:
1 = Phase rotation tester
1 = 2” copper pipe with union for connection of tank to water pump intake
1 = Water return Y-strainer/filter

NOTES

TABLE OF CONTENTS
Installation……………………………………….……………………………
1
Phase Sequence Test……………………………………………………….
2
Fuse and Wiring Chart………………………………………………………
3
Inter-module Wiring………………………………………………………….
4
Plumbing…………………………………………………………………......
5
Inter-module Hose Connecting…………………………...........................
7
First Power-up………………………………………………………………..
8
Dew Point Protection System (Option 8001-03) …………………………
9
Setting Temperature Controller…………………………………………….
10
Initial Startup………………………………………………………………….
11
Temperature Sequence……………………………………………………..
12
Control Panel and Fault Lights……………………………………………..
13
Condition Indicator Lights…………………………………………………..
13
Fault Lights
Low Water Flow…...………………………………..…………………
14
Low Freon Fault………………………………………..……………..
15
High Freon Fault…………………….………………………..……….
15
Dew Point Control Faults (Option 8001-03)………………………………
17
Bypass Chiller During Service……………………………………………...
18
Preventative Maintenance…………………………………………………..
19
Outside Plumbing Connection……………………………………………...
20
Wiring Schematic…………………………………………………………….
21
Dew Point Schematic (Option 8001-03)…………………………….…….
22
Assembly of optional mounting stand 8510……………………………….
23
Maintenance Record Sheet ………………………………………….…….
25

INSTALLATION
UNITROL MODEL 8500, 8501, 8550, 8551
1
1. Carefully uncrate all modules and inspect for external damage. If any damage is seen, do
not continue until a representative of the freight company views the damage, and a claim to
the freight company has been filed.
2. Install the chillers in a location that will keep the air intake (back of chiller with air filter) and
air exhaust (front of chiller with expanded metal plate) at least 36” from the nearest wall.
This is required to allow maximum air movement over the condenser coil.
a. Install the MAIN module A (with the temperature controls) on the left, and the
REMOTE modules on the right. Keep a space of about 24” between the modules.
b. If the optional STACKING STAND has been shipped with this system, assemble the
stand as shown on page 23. Then place the stand over MODULE A and put MODULE
C on top. The stacking stand has pockets to receive leg pads on MODULE C.
3. Install 2” brass pipes with union between the pump and right side of MODULE A and the
tank bulkhead fitting on the left side of MODULE B. When installing the pipe in MODULE B,
be sure to hold another wrench on the flats of the bulkhead to prevent any damage.
4. If desired, bolt the modules in place using the four mounting pads on the bottom of the
module’s legs.
5. Remove the front expanded metal panel on MODULE A and MODULE B. It is not necessary
to remove this front expanded metal panel on MODULE C.
6. Remove the water tank cover and untie the water float. Leave the water tank cover off for
now.
7. Check the nameplate to be sure that the line voltage matches the incoming service.
THIS CHILLER IS DESIGNED FOR INSIDE INSTALLATION.
ONLY CHILLERS PURCHASED WITH THE –OS (OUTSIDE)
KIT CAN BE INSTALLED OUTSIDE IN AREAS WHERE
THE AIR TEMPERATURE CAN FALL BELOW 45ºF, AND
SUCH INSTALLATION WILL VOID THE WARRANTY.
FAILURE TO ALLOW MINIMUM WALL CLEARANCE
WILL RESULT IN HIGH FREON TEMPERATURES AND
WILL VOID WARRANTY.

INSTALLATION
UNITROL MODEL 8500, 8501, 8550, 8551
2
Note that a chiller marked 480V will operate on 430V –500V. A chiller that is marked 230V will
operate on 208V –260V.
8. MODULE A:
a. LINE VOLTAGE: Run a flexible cable (liquid tight) through one of the grommeted hole
in the right side bottom of the base pan and up into the control panel.
b. Run the other end to a local fused disconnect. The fused disconnect should be no
more than 36” from the point of entry to the chiller.
c. Install slow blow (time delay) fuses in the fused disconnect and use connecting wire
per the FUSE AND WIRE CHART on the next page.
d. Connect the three power wires to terminals marked L1, L2, and L3. Use the supplied
phase sequence tester to be sure that the L1, L2, L3 sequence is correct.
9. MODULE B and MODULE C: Remove the right side panel of each chiller and remove the
black control box covers.
a. Run a flexible cable (liquid tight) through one of the grommeted hole in the right side
bottom of the base pan and up into the knockout on the black compressor junction
box to a local fused disconnect. The fused disconnect should be no more than 36”
from the point of entry to the chiller.
1. If an optional backpressure pump is installed on this chiller, connect the line
wires to the top of the fuse block.
IF PHASE SEQUENCE IS NOT CORRECT, OPERATING OF THE
CHILLER CAN DESTROY THE COMPRESSOR. DO NOT TURN ON
THE CHILLER UNTIL PHASE ROTATION IS CORRECT.
A PHASE SEQUENCE TESTER has been supplied with this chiller. To use:
1. Connect the three leads, marked A, B, and C to the incoming power lines to each
module matching the letters A, B, and C on the power terminal.
2. If the wires are connected correctly, the tester will show a CLOCKWISE rotation.
3. If the instrument shows a COUNTER-CLOCKWISE rotation, disconnect the power
from the wires, move wire from L2 to terminal L1, and move wire from L1 to terminal
L2.
4. Turn power on and verify that the instrument shows CLOCKWISE rotation. Do this for
each chiller module as you install them.

INSTALLATION
UNITROL MODEL 8500, 8501, 8550, 8551
3
b. Install slow blow (time delay) fuses in the fused disconnect and use connecting wire
per the FUSE AND WIRE CHART below.
c. Connect the three line voltage wires to the L1, L2, L3 terminals on the contactor inside
the black control boxes. Be sure that the phase sequence is correct. Follow
instructions in the previous paragraph (for MODULE A) for checking the phase
sequence.
FUSE AND WIRE CHART: Each module requires a separate power line with an external 3-pole
fused disconnect installed within 3 feet from each chiller. Install slow blow (time delay) fuses in
the fused disconnect and use connecting wire per the chart below FOR EACH MODULE.
CHILLER MODEL
LINE AND
PHASE
FUSE SIZE
TIME DELAY
MINIMUM WIRE
GAUGE
8500 & 8550 MODULE A
480/3
35A
10
8500 & 8550 MODULE A
WITH 10HP WATER PUMP
480/3
45A
8
8500 &8550 MODULE B
480/3
20A
12
8500 & 8550 MODULE B with
optional backpressure pump
480/3
30A
10
8500 MODULE C
480/3
14A
14
8550 MODULE C
480/3
20A
10
8501 & 8551 MODULE A
230/3
75A
8
8501 & 8551 MODULE B
230/3
70A
6
8501 & 8551 MODULE B with
optional backpressure pump
230/3
75A
6
8551 MODULE C
230/3
70A
6
10. GROUNDING: Be sure to connect a separate ground wire to the ground terminal
mounted on the base pan of MODULE A, and inside the black control box of
MODULES B and C. This wire should be sized to handle at least 50% of the nameplate
average amperage.
DO NOT OPERATE THESE CHILLER MODULES
WITHOUT A PROPER GROUND CONNECTED TO
THE GROUND LUGS ON EACH BASE PAN OR
CONTROL BOX.
IF PHASE SEQUENCE IS NOT CORRECT, OPERATING OF THE
CHILLER CAN DESTROY THE COMPRESSOR. DO NOT TURN ON
THE CHILLER UNTIL PHASE ROTATION IS CORRECT.

INSTALLATION
UNITROL MODEL 8500, 8501, 8550, 8551
4
INTER-MODULE WIRING
1. Route the interconnecting flexible cable (liquid tight) that comes from the MODULE A
through the grommeted holes in the base pans near the black junction boxes. Be sure
that you are running the cable marked MODULE B to MODULE B, and the cable marked
MODULE C to MODULE C. For MODULE B, the hole is on the left side. Run the flexible
cable across the basepan to reach the fitting on the black junction box.
2. Connect each cable to the waiting fitting on the side of each black junction box.
3. Wire each wire in the harness to the matching terminal in this enclosure.
4. Do not install the junction box cover or the right-side panel until after the INITIAL
STARTUP section of this book.
BE SURE TO PROTECT THE WIRE TAGS ON
THESE WIRES DURING INSTALLATION
INTO THE JUNCTION BOX.

INSTALLATION
UNITROL MODEL 8500, 8501, 8550, 8551
5
PLUMBING
PIPE SIZING CHART
CHILLER MODEL
MINIMUM HEADER SIZE
MINIMUM DOWN
RUNS
8500, 8501
1-1/2”
¾”
8550, 8551
2”
¾”
Note: On type “L” chillers (low flow models) pipe size may be reduced for low flow
applications. Consult Unitrol for sizing assistance.
Check the plumbing hookup diagram on page 20 to do the
following:
1. MAKEUP WATER: Install a water line to the MAKE-UP WATER IN port on MODULE B. A
1/2” hose is sufficient for this purpose. This will be used to keep the internal water tank filled
if there are any leaks in the outside water system. A float valve is provided in the water tank.
PIPE INSULATION
ALL PIPES FROM THE CHILLER AND RETURNING TO THE
CHILLER MUST BE INSULATED. COMMERCIAL SNAP-ON
FOAM INSULATION IS SUFFICIENT FOR THIS PURPOSE.
REASON #1: DURING WARM WEATHER THE INSULATION
WILL PREVENT CONDENSATION FROM THE PIPES.
REASON #2: EVERY SQUARE INCH OF ALL PIPES IN THE
SYSTEM WILL ACT AS AN EXCHANGE SURFACE FOR THE
CHILLER. IN OTHER WORDS, THE CHILLER WILL TRY TO AIR
CONDITION THE FACTORY. THE ENERGY USED IN THIS WAY
IS WASTED AND MIGHT LOWER THE ENERGY ABILITY OF
THE CHILLER TO A POINT LOWER THAN THAT REQUIRED
FOR THE MACHINE LOADS.

INSTALLATION
UNITROL MODEL 8500, 8501, 8550, 8551
6
Because this same pipe that feeds this makeup water line will be used to circulate water to
the machinery if the chiller is taken out of service, the pipe size should be at least 1-1/2”.
Install a TEE and shut off valve as shown in the plumbing diagram to allow the chiller to be
isolated for service purposes.
2. Y-STRAINER/FILTER: A valve is factory installed on this device to allow easy flush out of
dirt trapped in the filter without the need to turn off the system. It is not necessary to connect
this valve to a drain since water can be sent into a bucket whenever it is desired to flush out
this filter.
3. Install this Y-strainer/filter supplied with this chiller to the 2” bulkhead marked WATER
RETURN located on MODULE B.
4. Page 20 shows a recommended piping layout that allows the chiller to be taken offline and
fast switchover to the incoming plant water supply. It is highly recommended that you follow
this layout.
5. A DRAIN fitting is located on the front left corner of the MODULE B base pan. If desired, this
can be connected to a drain. The only time water will come out of this fitting is if the water
float malfunctions or is not adjusted properly.
WARRANTY IS VOID IF CHILLER IS OPERATED
WITHOUT THE Y-STRAINER FILTER INSTALLED
ON THE WATER RETURN LINE.

INSTALLATION
UNITROL MODEL 8500, 8501, 8550, 8551
7
INTER-MODULE HOSE CONNECTION
1. Install the four 1-1/4” hose supplied with this chiller from MODULE A to MODULE B and
MODULE C. The hoses and barbs are all color-coded for this purpose.
2. Tighten the hose clamps.
3. Install the 3/4” hose supplied with this chiller between the pressure BYPASS barb on
MODULE A to the BYPASS barb on MODULE B.
4. Tighten the hose clamps.
5. Set outside water valves as follows: TURN ON VALVES #3, #4, and M. TURN OFF
VALVES: #1, and #2
6. Remove the expanded metal panel on MODULE B.
7. Turn water on at the MAKE-UP WATER IN port and the tank should fill until the water float
valve closes. Be sure that the fill point is below the overflow bulkhead fitting on the tank.
While this float arm is factory adjusted, check to be sure that it fills the tank just under the
overflow bulkhead fitting. Adjust the float arm if. Leave the cover off.
HOSE CONNECTION HINT: Put a little grease or oil
on the tip of the hose barbs to make installation of
hoses easier.

INITIAL STARTUP
UNITROL MODEL 8500, 8501, 8550, 8551
8
FIRST POWER UP
1. Turn the MASTER ON/OFF switch to OFF.
2. Turn the customer fused disconnect bringing power into the MODULE A ONLY.
POWER UP PROCEDURE:
1. MODULE A: Turn the MASTER ON/OFF switch to the ON position. The temperature
controller and water pump should turn on.
2. The water pump pressure gauge should be showing pressures between 35 - 55psi. If lower
or higher pressures are shown, turn chiller off and contact the Unitrol service department at
847-480-0115 to discuss this problem.
3. Because you will be filling all of the outside pipes, it is possible that the water tank will drain
down. If this happens, turn the MASTER ON/OFF switch to OFF until the makeup valve has
filled the tank. You can see the water level as a shadow on the side of the water tank in
MODULE B.
4. Continue to do this until the water tank remains full when the pump is running.
DO NOT ALLOW THE PUMP TO GO DRY. OPERATING A
CHILLER PUMP WITHOUT AT LEAST 24” OF WATER
DEPTH IN THE WATER TANK CAN BURN OUT THE
PUMP SEALS.
NEVER TOUCH ANY WIRE CONNECTIONS UNTIL
YOU ARE SURE POWER HAS BEEN
DISCONNECTED. USE A METER OR VOLTAGE
TESTER TO BE SURE NO VOLTAGE EXISTS ON
THESE WIRES BEFORE ENTERING THE WIRING
COMPARTMENT.

INITIAL STARTUP
UNITROL MODEL 8500, 8501, 8550, 8551
9
DEW POINT PROTECTION SYSTEM
OPTION 8001-03
FUNCTION: When this option is installed, this option prevents the tank temperature from being
chiller below the DEW POINT of the factory air. Water that is below the dew point can cause
condensation inside water-cooled welding transformers that can, over time, damage or destroy
the welding transformer.
OPERATION: When the control is chilling the water, if the water temperature drops below the
DEW POINT at that moment:
1. The “snow flake” light on the controller will stop flashing
2. The refrigeration compressor will stop operation
3. The display will alternately display the tank temperature and the code: Dpl (dew point
lockout). This will continue until the tank temperature rises 3°F above the dew point
temperature of the room.
4. If the set point (SP) that was entered into the controller is below the water temperature,
the compressor will come on and chill the water down to the dew point.
EXAMPLE:
1. Controller is customer-set for 60°F (SP setting on the controller)
2. The DEW POINT of the room at that moment is 62°F
3. The water temperature in the tank is 66°F
4. The “snow flake” on the controller is flashing
5. The compressor is operating to chill the water
6. The water temperature in the tank now drops to 62°F (the DEW POINT)
7. The “snow flake” on the controller stops flashing
8. The compressor stops operation, but the water pump continues to operate
9. The display alternately shows the tank water temperature and
dPL

INITIAL STARTUP
UNITROL MODEL 8500, 8501, 8550, 8551
10
FIRST TURN ON: When the chiller is first turned on, the display will briefly show:
then
Then for about 30 seconds
Then
then
and finally the tank water temperature
Once this initial procedure has been completed, the compressor in MODULE A will turn on if
the temperature is at least 3°F above the SP number as customer-set in the next section.
SETTING TEMPERATURE CONTROL
1. Press the SEL button once on the control to display the current SP or SV (target
temperature). The compressor will operate if the water tank temperature is at least 3°F
above this SP or SV temperature and the water tank temperature is above the DEW
POINT at that moment.
2. If you want to change this number, press the SEL button a second time and then use
the ▲or ▼ button to increase or decrease the SP temperature.
3. When you are finished, press the SEL button to lock this number.
a. NOTE: If you do not push the SEL button after changing the SP temperature
value, the system will go back to the original SP or SV temperature (will not
change the target temperature). If you want to go back to display the tank water
temperature, press the ▲or ▼button at the same time twice and the tank water
temperature will be displayed.
4. For controls with 8001-03 optional DEW POINT control: If you want to view the DEW
POINT (d P), relative humidity (r H), room temperature (r T), or tank water temperature
888
--
E O
dPL
0 0

INITIAL STARTUP
UNITROL MODEL 8500, 8501, 8550, 8551
11
(t t), push the ▼button until you see the symbol for the value you want to view. Then
push the SEL button. When you are finished, push the ▲or ▼button at the same time
twice and the tank water temperature will be displayed.
5. Note that if you do not push the ▲AND ▼button at the same time twice, the display
will go back to the tank water temperature automatically in about 5 minutes.
If MODULE A is working properly, turn the MASTER ON/OFF switch OFF.
Turn on line voltage to MODULE B and MODULE C.
Turn the MASTER ON/OFF switch to ON.
IF ANY COMPRESSOR STARTS AND IS MAKING A VERY
LOUD GRINDING SOUND, TURN THE SYSTEM OFF
IMMEDIATELY AND CHECK THE PHASE SEQUENCE
FOR THAT MODULE. THIS NOISE WOULD INDICATE
THAT THE COMPRESSOR IS RUNNING BACKWARDS!
A COMPRESSOR RUNNING BACKWARDS WILL NOT
PUT OUT ANY HEAT TO THE FRONT OF THE MODULE.
RUNNING A COMPRESSOR BACKWARDS FOR MORE
THAN A FEW MINUTES CAN CAUSE PERMANENT
DAMAGE THAT IS NOT COVERED BY WARRANTY.

INITIAL STARTUP
UNITROL MODEL 8500, 8501, 8550, 8551
12
TEMPERATURE SEQUENCE
The chart below shows the operation of the three modules in response to the tank water
temperature and the customer-set SP (SV) temperature.
FOR CHILLERS WITH OPTIONAL DEW POINT CONTROL: IN ALL CASES BELOW, IF
THE TANK WATER TEMPERATURE IS BELOW THE DEW POINT, NO COMPRESSORS
WILL OPERATE. THE SYSTEM WILL WAIT UNTIL THE TANK WATER TEMPERATURE IS
ABOVE THE DEW POINT TEMPERATURE.
If the SP on the temperature controller is lower than the dew point temperature, then the
dew point temperature will become the lowest temperature possible.

INITIAL STARTUP
UNITROL MODEL 8500, 8501, 8550, 8551
13
CONTROL PANEL OPERATION AND FAULT INDICATOR LIGHTS
ON TEMPERATURE CONTROLLER
SV = Customer-set temperature target
A = Glows when controller turns on
compressor #1 in MODULE A
B = Glows when controller turns on
compressor #2 in MODULE B
C = Glows when controller turns on
compressor #3 in MODULE C.
ON CONTROL PANEL
Indicators for compressor
number shown
HIGH FREON FAULT: Glows when
Freon pressure is above 425psi. This
will prevent operation of the
compressor even if water temperature
is above the temperature controller set
point (SP or SV)
LOW FREON FAULT: Glows when
Freon pressure is below 50psi. This will
prevent operation of the compressor
even if water temperature is above the
temperature controller set point (SP or
SV)
FREEZESTAT FAULT: Glows when
water temperature in that module is
below 40°F. Note that the FREEZESTAT
controllers are factory set at 40°F and
cannot be adjusted.
LOW WATER FLOW: Glows when water
flow is below 5gpm in that circuit. This
will prevent the compressor from
turning on even if the temperature is
above the thermostat set point (SP or
SV).
SV
A
B
C
TEMPERATURE CONTROLLER FOR OPTIONAL
8001-03 DEW POINT CONTROLLER.

INITIAL STARTUP
UNITROL MODEL 8500, 8501, 8550, 8551
14
MODULE A, MODULE B, and MODULE C:
LOW WATER FLOW: Each module has a separate WATER FLOW switch.
When the red LOW WATER FLOW light glows, the compressor will not operate even if the
tank temperature is higher than the SP or SV value, but the water pump will continue
operation. It can be caused by several conditions:
1. The water pump is not operating correctly. This can be caused by
a. A motor failure on the pump
b. An internal broken pump impeller
c. A 3Ø pump motor operating in the incorrect rotation
2. A foreign object has been sucked into the water pump intake port (bulkhead at bottom of
tank).
3. A problem with the MOTOR STARTER contactor K1.
a. The overload on the water pump MOTOR STARTER K1 has tripped. The reset
button on the overload can be pushed to reset the contactor. However the cause
should be found and corrected. Otherwise this contactor will continue to trip. Tripping
of the overload can be caused by one of the following conditions:
i. One line of the 3-phase incoming power has been lost causing “single
phasing” of the motor.
WHY THE LOW WATER FLOW SAFETY SWITCHES ARE IMPORTANT
If the water flowing through the evaporators (chilling component) of either
refrigeration system is too low, the water deep in that evaporator can easily
reach temperatures below freezing.
When this happens, the evaporator can eventually crack from the expanding
ice. This will cause a break between the water system and the refrigeration
Freon system destroying the evaporator.
When this happens, the Freon will blow out of the system through the water
tank, and water will enter the refrigeration section. Permanent damage can
easily occur to the compressor at this point.
DO NOT DEFEAT THE WATER FLOW SAFETY SWITCH!