Yazaki Aroace WFC-SC10 User manual

WATER-FIRED SINGLE-EFFECT
ABSORPTION CHILLER
This product is a water-fired single-effect absorption unit which provides chilled
water for cooling in central plant type air conditioning systems. WFC-SH model chiller-
heaters also provide hot water for heating in two-pipe central plant type systems. Units
with nominal refrigeration capacities of 10, 20, 30, and 50 tons are complete with
operating and safety controls. The absorption chiller or chiller-heater is energized by a
heat medium (hot water) from a process, cogeneration, solar, or waste heat source
capable of providing a temperature range of 158 –203°F (70 –95°C).
CONTENTS
GENERAL Page
GENERAL 2
MODEL DESIGNATION 2
ACCESSORIES 2
STANDARD SPECIFICATIONS 3
CONTROL ADJUSTMENTS 4
EQUIPMENT DIMENSIONS 5
TYPICAL SYSTEM DESIGN 7
WIRING DIAGRAMS 8
INSTALLATION
RIGGING AND MOVING 11
LOCATION AND CLEARANCES 13
FOUNDATION 13
LEVELING 14
PIPING 14
Page
CHILLED/HOT WATER PIPING 15
COOLING WATER PIPING 15
HEAT MEDIUM PIPING 16
FREEZE PROTECTION 16
ELECTRICAL 17
HIGH VOLTAGE CONNECTIONS 18
CONTROLLING PUMPS AND
VALVES 18
COOLING TOWER FAN CONTROL 19
PUMP SAFETY INTERLOCKS 19
BUILDING MANAGEMENT
SYSTEM INTERFACE 20
REMOTE MONITORING 20
WATER QUALITY 22
INSTALLATION CHECK &
REQUEST FOR STARTUP 22
INSTALLATION INSTRUCTIONS
WFC-SC10, 20, 30, 50
WFC-SH10, 20, 30

2
GENERAL
This equipment should only be installed
by trained and qualified personnel who are
familiar with absorption chillers. All
precautions in these instructions, as well as
on tags and labels attached to the unit, must
be observed to ensure the safety of the
personnel and maintain warranty validation.
Each Yazaki absorption chiller or chiller-
heater has been evacuated, charged with
lithium bromide and water solution, and run
tested prior to leaving the factory.
Field wiring connections are located on
the left side of the unit when facing the front
of the unit, except on the WFC-SC50, which
has them located at the rear of the unit. In
all sizes, piping connections are all located at
the rear of the unit.
After the equipment has been installed, a
Yazaki Authorized Service Provider (ASP)
must check the installation and supervise or
conduct the initial startup and operation of
the unit.
CAUTION
THE YAZAKI WARRANTY WILL BE
VOIDED IF THE FOLLOWING
RESTRICTIONS ARE NOT OBSERVED:
1. DO NOT OPEN ANY SERVICE VALVES
WITHOUT A PROPER EVACUATION
ASSEMBLY ATTACHED TO THEM AS SUCH
ACTION WILL RESULT IN LOSS OF
VACUUM AND INTRODUCTION OF GASES
TO THE INTERIOR OF THE MACHINE
WHICH COULD CAUSE CORROSION.
2. ALWAYS HANDLE THE EQUIPMENT WITH
CARE AND MAINTAIN IN A NEAR-
VERTICAL POSITION DURING RIGGING. IF
THE EQUIPMENT MUST BE TILTED,
CAREFULLY FOLLOW INSTRUCTIONS
PROVIDED WITHIN THIS DOCUMENT.
3. DO NOT ATTEMPT TO START THE
SYSTEM WITHOUT SUPERVISION FROM A
YAZAKI AUTHORIZED SERVICE PROVIDER
(ASP).
MODEL DESIGNATION
WFC-S C 10
Water-Fired Chiller with Integrated Solution Pump
C - Cooling Only Design; H –Heat/Cool Design
Cooling Capacity: 10 –10 rated tons
20 –20 rated tons
30 –30 rated tons
50 –50 rated tons
ACCESSORIES
Provided with the Chiller/Chiller-Heater: Optional Accessories:
ACT-3 Maintenance Checker (1) Arotrend Remote Monitoring
Eye bolts (4) FS2 Cooling Water Flow Switch
Shims (6) {except on WFC-SC50} LON Adapter for BMS Interface
Installation Instructions (1) WFC-S Service Manual
Operating Instructions (1) WTI Inlet Chilled/Hot Water Sensor
L-Anchor Plates {with WFC-SC50 Only} Heat Medium Bypass Valve Kits

3
STANDARD SPECIFICATIONS
Specifications
WFC-
SC10
SH10
SC20
SH20
SC30
SH30
SC50
Cooling Capacity
MBTUh (kW)
120.0 (35.2)
240.0 (70.3)
360.0 (105.5)
600.0 (175.8)
Heating Capacity
MBTUh
(kW)
---
166.3
(48.7)
---
332.6
(97.5)
---
498.9
(146.2)
---
Chilled/Hot Water
Temperature
Cooling
°F (°C)
54.5 (12.5) Inlet / 44.6 (7.0) Outlet
Heating
°F (°C)
117.3 (47.4) Inlet / 131.0 (55.0) Outlet / {WFC-SH Models Only}
Evaporator Pressure Loss
PSI (kPa)
8.1 (55.8)
9.6 (66.2)
10.1 (69.6)
6.4 (44.2)
Max Operating Pressure
PSI (kPa)
85.3 (588.1) / {High Pressure Option Available on WFC-SC50 only}
Rated Water Flow
GPM (l/s)
24.2 (1.5)
48.4 (3.1)
72.6 (4.6)
121.1 (7.6)
Allowable Water Flow Range
% of Rated
80% - 120%
Water Retention Volume
Gal (liters)
4.5 (17.0)
12.4 (46.9)
19.3 (73.1)
33.6 (127.2)
Cooling Water
Heat Rejection
MBTUh (kW)
291.4 (85.4)
582.8 (170.8)
874.2 (256.2)
1457.0 (427.0)
Temperature
Cooling
°F (°C)
87.8 (31.0) Inlet / 95.0 (35.0) Outlet
Absorber Pressure Loss
PSI (kPa)
12.3 (84.8)
6.6 (45.5)
6.7 (46.2)
6.6 (45.3)
Condenser Pressure Loss
PSI (kPa)
Included in
Absorber
6.6 (45.5)
6.7 (46.2)
3.2 (21.9)
Max Operating Pressure
PSI (kPa)
85.3 (588.1) / {High Pressure Option Available on WFC-SC50 only}
Rated Water Flow¹
GPM (l/s)
80.8 (5.1)
161.7 (10.2)
242.5 (15.3)
404.5 (25.5)
Allowable Water Flow Range
% of Rated
100% - 120%
Water Retention Volume
Gal (liters)
17.4 (65.9)
33.0 (124.9)
51.3 (194.2)
87.2 (330.1)
Heat Medium
Heat Input
MBTUh (kW)
171.4 (50.2)
342.8 (100.5)
514.2 (150.7)
857.0 (251.2)
Temperature
°F (°C)
190.4 (88.0) Inlet / 181.4 (83.0) Outlet
Allowable Temperature Range
°F (°C)
158.0 - 203.0 (70.0 - 95.0)
Generator Pressure Loss
PSI (kPa)
13.1 (90.3)
6.7 (46.2)
8.8 (60.7)
13.6 (93.7)
Max Operating Pressure
PSI (kPa)
85.3 (588.1) / {No High Pressure Option}
Rated Water Flow
GPM (l/s)
38.0 (2.4)
76.1 (4.8)
114.1 (7.2)
190.4 (12.0)
Allowable Water Flow Range
% of Rated
30% - 120%
Water Retention Volume
Gal (liters)
5.5 (20.8)
14.3 (54.1)
22.2 (84.0)
39.7 (150.3)
Electrical
Power Supply
208 volts AC / 60 Hz / 3-Phase
Consumption²
Watts
210
260
310
670
MCA
Amps
0.6
0.9
2.6
4.7
MOCP
Amps
15
Construction
Dimensions³
Width
Inches (mm)
29.9 (760)
41.7 (1060)
54.3 (1380)
70.3 (1785)
Depth
Inches (mm)
38.2 (970)
51.2 (1300)
60.8 (1545)
77.2 (1960)
Height
Inches (mm)
74.8 (1900)
79.1 (2010)
80.5 (2045)
82.1 (2085)
Weight
Dry
lbs (kg)
1100 (500)
2050 (930)
3200 (1450)
4740 (2150)
Operating
lbs (kg)
1329 (603)
2548 (1155)
3975 (1800)
5955 (2700)
Noise Level
dB(A)
49
46
51
Piping
Chilled/Hot Water
Inches
1-1/2 NPT
2 NPT
3 NPT
Cooling Water
Inches
2 NPT
2-1/2 NPT
3 NPT
Heat Medium
Inches
1-1/2 NPT
2 NPT
2-1/2 NPT
3 NPT
Note: All metric values are calculated from the Imperial values and are only approximate values.
1 - Minimum cooling water flow is 100%.
2 - Power consumption does not include external pumps or motors.
3 - Width/Depth does not include the junction box or mounting plates. Height does not include the removable lifting lugs but does include level bolts.
Table 1 - Specifications

4
EQUIPMENT DIMENSIONS
(Drawings are not to scale)
WFC-(SC,SH)10
WFC-(SC,SH)20

5
WFC-(SC,SH)30
WFC-SC50

6
TYPICAL SYSTEM DESIGN
EXAMPLE OF A SINGLE MODULE
EXAMPLE OF MULTIPLE MODULES

7
WIRING DIAGRAMS
Figure 1 –Internal Wiring Diagram

8
TERMINALS
SYMBOL
LOCATION
REMARKS
Control Box
Junction Box
Field wiring
connections
Control Box
(I/O Board)
Molex Connector
STANDARD JUNCTION BOX
CONNECTIONS
TERMINAL
DESCRIPTION
REMARKS
3 (P1E)
Chilled/hot water
pump safety
interlock
Safety interlocks
MUST be
connected or the
unit will lock out
with pump/fan
error codes.
4 (P2E)
Cooling water
safety interlock
5 (FE)
Cooling tower fan
safety interlock
6 (P3E)
Heat medium
pump safety
interlock
CM1
Common to
terminals CP,
CTF, P, P3A, P3B
No voltage
supplied by
WFC-S unit on
this terminal
CM2
Common to
terminals
3, 4, 5, 6
WFC-S unit
supplies 15vdc
on this terminal
CP (P2)
Cooling water
pump demand
Dry contacts,
24v, 60va max
load
P (P1)
Chilled/hot water
pump demand
P3A
Heat medium
bypass valve –
demand position
P3B
Heat medium
bypass valve -
bypass position
S3, S4
Heat medium
pump demand
SOLUTION PUMP OVERLOAD SETTINGS
SYMBOL
WFC MODEL (*208 Volts AC)
SC/SH10
SC/SH20
SC/SH30
SC50
THRP
0.4
0.7
2.0
4.5
*Power supply tolerance is +10%, -5%
FUSE RATING
SYMBOL
AMPS (A)
REPLACEMENT
F2
3
Bussman GLQ-3
or GMQ-3.2,
rated 300vac
F4,
F11, F12
2
Fuji FGAO-2,
rated 250vac
FT1, FT2
5
Fuji FGAO-5,
rated 250vac
INTERNAL WIRING
SYMBOL
DESCRIPTION
REMARKS
CTI
Cooling water inlet
temperature sensor
CVR
Changeover valve
Only on SH
models
F2, F4,
F11, F12,
FT1, FT2
Fuses
Refer to Fuse
Rating Table
FS1
Chilled/hot water
flow switch
HWT
Heat medium
temperature sensor
LT
Evaporator
temperature sensor
LTPV
Refrigerant
proportional
control valve
MP
Solution pump motor
contactor
RMP, RP3,
RV9, RBO
Control relays
5 amp, 250v
max load
SA1, SA2
Surge absorbers
SP
Solution pump
SV1
Evaporator freeze
protection valve
SV9
Concentrated solution
bypass valve
SV11
Refrigerant
drain valve
Only on SH
models
THRP
Solution pump
thermal overload
TR-LV
Low voltage
transformer
24vac primary /
18, 15vac dual
secondary
WFC-TRUL1
Class 2 transformer
208vac primary /
24vac secondary
WTO
Leaving chilled/hot
water temp sensor
OPTIONAL JUNCTION BOX CONNECTIONS
TERMINAL
DESCRIPTION
REMARKS
1, 2
(DCP)
Arotrend Remote
Monitoring connection
For use with
Optional
Arotrend System
7, 8
LON Adapter
connection
For use with
Optional
Factory-Installed
LON Adapter
A (C1)
Remote cool mode
selection
Remote control
(BMS) interface.
ONLY USE DRY
CONTACTS to
control these
signals!
B (H1)
Remote heat mode
selection
C (CHON)
Remote "Enable"
signal
D (CHOFF)
Remote "Disable"
signal
E (CM3)
Common for
A, B, C, D
The WFC-S unit
outputs 15vdc on
this terminal
CTF
Cooling tower fan
cycling control
Dry contacts.
24v, 60va max
load.
S5, S6
Heat mode
feedback relay
S7, S8
Cool mode
feedback relay
S11, S12
"Enabled" mode
feedback relay
S13, S14
Alarm feedbackrelay

9
OPTIONAL CONTROL BOX CONNECTIONS
TERMINAL
DESCRIPTION
REMARKS
2, 3 on
CN11
(FS2)
Cooling water flow
switch
Field-installed
option
S9, S10
(BO)
Auxiliary boiler
control relay
Dry contact, 24v,
60va max load.
Closes at 185°F
(85°C), Opens at
194°F (90°C).
TB1-7,
TB1-8
(ST2)
Safety shut down
Shuts unit down
in under 6
seconds.
Configurable for
NC or NO
contacts.
TERMINAL
DESCRIPTION
REMARKS
TB1-9,
TB1-10
(IF1)
Chilled/hot water
circuit freeze
protection logic
If the terminals
are jumped, the
WFC-S unit will
use its internal
freeze protection
logic to turn on
pumps when the
fluid circuit is
sensed to be
approaching
freezing.
TB1-11,
TB1-12
(IF2)
Cooling water
circuit freeze
protection logic
TB3-7,
TB3-8
(CHSTN)
"Disabled"
feedback relay
Dry contact, 24v,
60va max load.
TB3-17,
TB3-18
(AL)
Alarm
Figure 2 –Controls Wiring Diagram

10
Figure 3 –Field Wiring Diagram as Supplied in the Junction Box
INSTALLATION
RIGGING AND MOVING
When the absorption chiller or chiller-
heater is delivered, it should be inspected for
transit damage. Should any damage be
found, do not proceed with installation until
the Yazaki distributor has been notified and
any required remedial actions have been
completed.
Table 2 –Hallway Clearances
Remember to properly plan the route to
the installation site. Also, keep in mind when
choosing the site that the unit will someday
have to be removed, so be mindful of
permanent and semi-permanent barriers.
The Yazaki chiller-heater is designed for
overhead rigging with lifting lugs provided
from the factory.
Figure 4 –Rigging
WFC MODEL - Inches (mm)
SC/SH10
SC/SH20
SC/SH30
SC50
A
93 (2060)
98 (2490)
100 (2540)
B, C
63 (1600)
75 (1900)
88 (2235)
102 (2590)

11
When rigging for overhead lift, attach
shackle bolts to the lifting lugs. Bring the
four individual rigging cables together at a
point high enough that the angle between the
rigging line and the top of the unit is no less
than 60°, as shown in the Figure 4. This will
require cable lengths a minimum of 36” (1m)
for all sizes except the WFC-SC50 which will
require 48” (1.3m) cable length.
There are times when the unit simply
cannot be moved to the final installation site
while remaining in the vertical position. It is
be permissible to lay the unit on its side, so
long as proper precautions and guidelines
are followed.
Figure 5 –Laying the Unit on its Side
1. Transport by vehicle ONLY with the unit in
vertical configuration. THERE IS NO
ALTERNATIVE. Transport by vehicle over
roadway while the unit is not in the vertical
configuration will void the warranty.
2. The unit may ONLY lay onto its back - the side
with the water connections. It may NOT lay on
any other side!
a. While on its back, the water piping acts as
legs to support the internal tubing bundles.
On any other side, the tubing bundles will
not be properly supported and may shift or
become severely damaged, rendering the
machine inoperable.
3. Do not simply tip the unit over onto its back. It
should be lifted and turned to the horizontal
configuration while fully supported and
suspended, though it only need be barely off
the ground while turning.
4. DO NOT lay the unit directly onto the ground
in a manner that will allow the water
connections support the weight of the unit.
Attach 4x4 blocks or timbers to the frame for
support in the horizontal configuration.
5. DO NOT USE A SINGLE POINT LIFTING
when laying the unit onto its side. At least
THREE lifting points will be necessary.
To properly lay the unit onto its side:
1. Remove all cabinet panels in order to prevent
damage to them.
2. Attach 4x4 blocks or timbers to the rear frame
to act as support feet while the unit is in the
horizontal configuration.
3. Attach two rigging cables to the unit feet
across the front of the unit. Bring these cables
to a single point, maintaining a minimum of
60° between unit and cable.
4. Attach two rigging cables to the left side lifting
lugs. Bring these cables to a single point.
5. Attach two rigging cables to the right side
lifting lugs. Bring these cables to a single
point.
6. Using these three points, lift the unit slightly off
the ground, using the lifting cables on the feet
to rotate the unit onto its back. Use the right
and left side lifting cables to control the
sideways rotation.
7. Once the unit is in the horizontal configuration,
let it gently rest on the blocks that were
attached during step 2.
8. Once the unit is to be turned back to the
vertical configuration, it is preferable that the
unit again be lifted and rotated in the same
manner as described above. However, in
cases where mechanical lifting is not available
at the installation site, the unit CAN tilted over
onto its feet.
Do not let the unit fall hard onto its feet.
Do not allow the feet to become deformed.
Be mindful of the considerable mass of
the unit (refer to the Specifications page).
Using human power alone to tip the unit is
not advised as it could become a very
dangerous and potentially deadly procedure.

12
LOCATION AND CLEARANCES
Particular care must be taken when
placing the machine so as to provide
adequate clearance for access to each side
of the machine. Maintenance is mostly done
through the front of the unit, but in a repair
scenario, any panel on any side may need to
be removed to access components behind
them. The minimum space requirements
shown below must be provided around and
above each unit for installation and service
access.
Unit
WFC-
Installation Area
Maintenance Clearances
A
B
C (Front)
D (Back)
E (Left)
F (Right)
SC10
67.9" (1725 mm)
116.2" (2952 mm)
39"
(1000 mm)
39"
(1000 mm)
28"
(700 mm)
10”
(250 mm)
SC20
79.7" (2025 mm)
129.2" (3282 mm)
SC30
92.3" (2345 mm)
141.0" (3582 mm)
SC50
126.1" (3203 mm)
154.8" (3932 mm)
28”
(700 mm)
SH10
85.9" (2182 mm)
116.2" (2952 mm)
SH20
97.7" (2482 mm)
129.2" (3282 mm)
SH30
110.3" (2802 mm)
141.0" (3582 mm)
Table 3 –Required Installation Area and Maintenance Clearances
FOUNDATION
All aspects of foundation and support
computations must be in accordance with
national and local codes.
The chiller must be mounted on a level,
non-combustible foundation capable of
supporting the considerable weight of the
machinery. This is particularly important for
rooftop installations. Always make certain
the structure can support not only the full
mass of the chiller, but also the pumps,
piping, cooling towers, etc. as may be
required. The rooftop area should be well-
drained and be at least 7 feet (2m) from the
edge of the roof. Anti-fall measures should
always be taken if the chiller is installed
within 12 feet (4m) of the roof edge.
Additionally, for protection of the roofing
material, it is recommended a suitable
platform or walkway be provided around all
sides of the unit.
If the chiller is to be installed outside, but
at ground level, make certain the concrete
base and the soil beneath are sufficient for
the task. Settling over time could cause the
unit to become un-level, which could have a
serious, negative impact on the performance
and lifespan of the unit. Concrete
foundations are recommended to be sized so
that it extends at least 12” (300 mm) beyond
the unit in all directions in order to
accommodate potential mounting and
anchoring hardware.
Figure 6 –Foundation Detail

13
WFC-(SC,SH)10, 20, 30 WFC-SC50 Units Only
Figure 7 –Securing the Unit to the Foundation
LEVELING
WFC-S Series units must be level in order
for the fluids to be distributed properly over
their respective tube bundles. There is a
level bar mounted on the front of the main
vessel of the machine, right above the
control box.
The unit must be level to both the
longitudinal and transverse alignments. It is
essential that all leveling be completed
before any piping connections are attempted.
Leveling of the unit is typically
accomplished by use of factory-supplied
metal shims, except for the WFC-SC50
which uses level bolts instead. In cases
where the unit is required to be secured to
the pad, anchor bolts, nuts, and washers
must be field-supplied.
Figure 8 –Level Bar
PIPING
After the chiller has been leveled properly,
the piping for the chilled water, cooling water,
and heat medium circuits may be installed.
Piping should be arranged so that there is no
interference with service access or panel
removal and should be adequately supported
and braced independently of the unit so as to
avoid undue strain on the unit piping
connections. Maximum allowable pressure
in any fluid circuit is 85.3 PSI (588 kPa).
Piping rules and conventions used with
Yazaki chillers and chiller-heaters are exactly
the same as those used with any other type
of chiller; therefore, this installation manual
will not delve deeply into piping design.
Thermo-wells, pressure gauges, etc. may
be installed at the inlet and/or outlet of each
fluid circuit connection to facilitate startup
and future routine maintenance. Strainers in
each circuit, particularly the cooling water
circuit, are recommended as well. These
should be placed before the inlet connection
of the pump. Also, ensure that unit panels
are not restricted by the pipe insulation.
When setting the flow through each fluid
loop, consult the Pressure Loss in Unit tag,
located on the frame just below and to the
left of the control panel. This tag often
shows values that are different than
submittals or spec sheets, including the ones

14
in this document. The values on the tag
must be used in lieu of any other values.
During the run test at the factory, the
pressure drop listed on this tag was
observed to be the exact pressure drop of
the unit when all other conditions were at the
design conditions. Each chiller in a group
may have individual and unique values as no
two tubing bundles are exactly alike.
Figure 9 –Example of the Pressure Loss
in Unit Tag
When setting proper flow rates through a
fluid loop, it will be necessary to measure the
pressure at both the inlet and the outlet of
the same circuit, and then subtract the higher
value from the lower value. The result is the
pressure drop through that circuit. The
target pressure drop is the value listed on the
Pressure Loss in Unit tag (see Figure 9).In
order to ensure proper flow through the fluid
circuits, make certain the pressure drop
through the loop is equal to or slightly greater
than the value listed on the Pressure Loss in
Unit tag.
Each inlet and outlet tube has a pressure
test needle valve installed into it. This
needle valve has a special metric flare
connection so it requires a specialized tool,
available from Yazaki, in order to access the
fluid circuit for pressure readings.
As an alternative, there is an accessory
kit available to replace the metric flare
needle valves with ¼” SAE flare valves. It
may also be possible to procure ¼” SAE
flare needle valves locally for the purpose.
FLOW SWITCH
The factory-installed flow switch is
shipped disconnected from the water piping
in order to help prevent damage during
shipment. After the factory run test is
completed, the flare nuts that connect the
water pipes to the differential pressure flow
switch are disconnected and plugged with a
small plastic cap.
One of steps of the installation process is
to locate the flow switch, remove the plastic
plugs, and attach the flare nuts to the flow
switch once again. If this step is forgotten,
then water will leak from these pipes as the
fluid circuit is being filled.
The flow switch must be set in order to
perform properly. In order to set the switch,
reduce the pressure drop through the
chilled/hot water circuit to ½ of the value
listed on the Pressure Loss in Unit tag,
adjust the flow switch until it opens at this
pressure setting, then restore the chilled/hot
water circuit to the normal pressure drop.
This method will test simultaneously set up
the flow switch as well as test its function.
CHILLED/HOT WATER PIPING
Figure 10 –Chilled Water Piping
CAUTION
1. DO NOT EXCEED 80 –120% OF
STANDARD CHILLED WATER FLOW.
2. DO NOT EXCEED 85.3 PSI (588 kPa) IN THE
CHILLED WATER CIRCUIT AT THE
ABSORPTION CHILLER.
3. DO NOT INSTALL ANY VALVES IN THE
EXPANSION LINE.
A balance valve should be installed at the
chilled water outlet and a stop valve should
be installed at the chilled water inlet.
After thoroughly testing for leaks, insulate
the piping circuit, ensuring an adequate
vapor barrier is obtained. Be sure to allow
access to any valves, wells, and ports that
may be present.

15
COOLING WATER PIPING
Figure 11 –Cooling Water Piping
CAUTION
1. DO NOT EXCEED 100 –120% OF
STANDARD COOLING WATER FLOW.
2. DO NOT EXCEED 85.3 PSI (588 kPa) IN THE
COOLING WATER CIRCUITS AT THE
ABSORPTION CHILLER.
3. DO NOT INSTALL ANY VALVES IN
EXPANSION LINES, WHEN USED.
If possible, the cooling tower should be
installed at the same level or above the level
of the chiller-heater. If this is not possible,
give careful consideration to the prevention
of drain-back and loss of cooling water due
to overflow of the tower. Such matters must
be given prior consideration by the design
engineer.
As with the chilled water connections, a
balance valve should be installed on the
cooling water outlet and a stop valve
installed on the cooling water inlet. Both
valves should be in close proximity to the
chiller. After thoroughly testing for leaks,
insulate the piping circuit, ensuring an
adequate vapor barrier is obtained. Be sure
to allow access to any valves, wells, and
ports that may be present.
Additionally, there should be flush and
drain valves installed between the machine
and the balance/stop valves so as to allow
for flushing of the absorber-condenser coils
should it ever become necessary.
One important element in the cooling
water piping is the Cooling Water Crossover
(not used on 10 ton units).This is always field-
supplied. It is recommended that balance
valves be installed on the outlets of both the
Condenser and Absorber in order to be able
to properly balance the flow through each
tubing bundle in accordance to the Pressure
Drop in Unit tag. The crossover tubing sizes
are listed below.
Figure 12 –Crossover Piping
MODEL
WFC-
COPPER TUBING
STEEL TUBING
A
B
A
B
SC/SH20
3"
2"
3-1/2"
2-1/2"
SC/SH30
3"
2-1/2"
4"
3"
SC50
4"
3"
5"
3-1/2"
If piping size reduction is required, it should be done at the unit.
All sizes listed are minimum sizes.
Table 4 –Crossover Piping Tube Sizes
CROSSOVER PIPING NOTES:
1. Installing flow balancing valves in each circuit
outlet is recommended.
2. Install cooling water flow valves at least 5 pipe
diameters upstream and/or downstream of
their respective “T” fittings.
3. The crossover pipe configuration must allow for
clear access to the rear of the chiller for
maintenance.
HEAT MEDIUM PIPING
The Heat Medium Piping contains the hot
water to drive the absorption system.
Provided this water remains between 158-
203°F (70-95°C), refrigerant vapor can be
generated in a usable quantity. If a mixing
valve is to be used to control this
temperature, IT MUST NOT BE COMBINED
WITH THE HEAT MEDIUM BYPASS
VALVE. It MUST be a separate and distinct
control.

16
Figure 13 –Heat Medium Piping
CAUTION
1. DO NOT EXCEED 30 –120% OF
STANDARD HEAT MEDIUM FLOW.
2. DO NOT EXCEED 85.3 PSI (588 kPa) IN THE
HEAT MEDIUM CIRCUIT AT THE
ABSORPTION CHILLER.
3. DO NOT INSTALL ANY VALVES IN THE
EXPANSION LINE.
The key device required for the proper
operation of the unit is a Heat Medium
Bypass Valve. When the unit requires heat
medium, it will send a signal to this valve to
open. When the unit does not require heat
medium, for whatever reason, this valve will
be commanded to move into bypass
position.
Figure 14 –Heat Medium Bypass
Valve (HMV) Installation
Valves and actuators are available in
accessory kits and those kit items are used
in the illustration in Figure 14. The fact that a
particular brand or type of valve and actuator
is used in the accessory kit should not be
taken as an endorsement or preference for
the brand of components used in the
accessory kit. Specific wiring instructions
are included in the accessory kit.
A balancing valve should be installed at
the heat medium outlet to facilitate flow rate
adjustments. An isolation valve should be
installed at the heat medium inlet and must
remain fully open at all times when the unit is
intended to operate.
A balancing valve, usually a ball valve,
should be used in the bypass line. This
valve should be used to set the pressure
drop through the bypass line to be equal to
the pressure drop through the heat medium
circuit of the unit.
AFTER LEAK TESTING, insulate the
piping to help prevent heat loss. Ensure that
all stop valves, balancing valves, and
thermowells are accessible.
FREEZE PROTECTION
When the chiller/chiller-heater and/or
associated piping are installed in a location
that may be subjected to freezing conditions,
appropriate freeze protection steps must be
taken. Many methods are available but the
most common method is the use of glycol.
Glycol may be permitted for use in Yazaki
chiller-heaters with certain precautions:
1. Do not use automotive glycol (Antifreeze) since
it may contain chemical additives that could be
inappropriate and potentially damaging to the
Yazaki chiller-heater. Use only glycol
appropriate for use with copper tubing and
brass fittings.
Exception: The heat medium circuit is
constructed of stainless steel so glycol used in
this circuit must not corrode that material.
There is no copper or brass in this circuit.
2. Do not exceed a mixture of 50% by weight.
3. Be aware that loss of performance will result
when glycol is used. The impact can become
very significant.
4. Propylene Glycol is preferred over Ethylene
Glycol. There is little difference in anti-freeze
characteristics, PG is non-toxic, and PG is
also less viscous than EG, reducing the
required pump power.
5. Use of glycol can cause the unit to operate at
higher internal temperatures. This may cause
faster depletion of inhibitor than what may be
perceived as normal.

17
ELECTRICAL
Figure 15 –Junction Box
Each absorption chiller/chiller-heater is
factory-wired for the specific voltage listed on
the Unit Nameplate. The standard field
wiring connections are provided in the
junction box located on the left side of the
unit on all models except for the WFC-SC50
model which has the junction box located at
the back.
Optional field wiring connections for
accessories and alarms are provided in the
junction box as well as in the control box.
All absorption chillers/chiller-heaters must
be electrically grounded and field wiring
installed in accordance with the National
Electrical Code (NFPA 70, latest edition).
HIGH VOLTAGE CONNECTIONS
The high voltage wiring should connect to
L1, L2, L3, and G in the left section of the
junction box, shown in Figure 15.
Check the voltage of each leg to ground.
Whichever leg has the greatest deviation
from the other two legs (the high leg or “wild”
leg) should be terminated on L2.
Use of phase-monitors to protect the
motor of the solution pump is recommended
in areas where power supply voltage is
known to be unstable.
Phase rotation should be checked at
these terminations as well. A phase rotation
meter is recommended to be used since the
amp draw of the solution pump is so low that
it is difficult to use that to determine proper
loading of the pump motor. While almost
any brand of phase rotation meter will do, the
Hioki 3126 is suggested.
Figure 16 –Hioki 3126 Rotation Meter
The proper rotation by rotation meter is
Clockwise. If the rotation detected is
incorrect, reverse the rotation by turning off
power to the unit, swapping the wires
terminating at L1 and L3, turning power back
onto the unit, and verifying proper rotation.

18
CONTROLLING PUMPS AND VALVES
The unit logic should control the pumps
and/or heat medium bypass valve rather
than any remote system such as BMS.
Field-supplied voltage is provided to terminal
CM1 in the junction box. This voltage is then
controlled through dry-contact relays by the
unit logic. See Figure 3 –Controls Wiring
Diagram for further details.
1. Chilled Water Pump Control: The unit
logic will output the voltage provided to
terminal CM1 to terminal P when the
chilled/hot water pump is demanded.
2. Cooling Water Pump Control: The unit
logic will output the voltage provided to
terminal CM1 to terminal CP when the
cooling water pump is demanded.
3. Heat Medium Pump Control: To control
the heat medium pump, use the dry contact
terminals S3 and S4 in the right section of
the junction box. A jumper may be placed
between CM1 and S3 if necessary to
provide voltage for the dry contacts. Unit
logic will close the factory-supplied dry
contacts between terminals S3 and S4
when the heat medium pump is demanded.
4. Heat Medium Bypass Valve Control: To
control the heat medium bypass valve, the
unit logic will output the voltage provided to
CM1 to terminal P3A when the unit logic
wants heat medium flow through the
chiller/chiller-heater. Similarly, the unit
logic will output the voltage provided to
CM1 to terminal P3B when the unit logic
wants the heat medium flow to bypass the
chiller/chiller-heater.
While it is preferable to have both a Heat
Medium Bypass Valve and control of the
Heat Medium Pump (P3), there are times
where this simply cannot be accomplished.
In such cases, by using modified wiring, just
having one of these two devices is enough to
control heat medium flow through the unit.
If the unit has a Heat Medium Bypass
Valve (HMV), but does not have control of the
P3 pump, then wire the valve as shown in
Figure 17. This configuration will allow any
alarms or control signals that would normally
be directed to the P3 pump to act on the
HMV instead. If only one device is possible,
the HMV is the preferred device as it will
provide positive shut off during the off cycle,
preventing any possible thermal siphoning.
Figure 17 –No Control of Heat Medium Pump
If the unit has control of the P3 but not of
the HMV, or there is no HMV at all, then wire
the P3 pump as shown in Figure 18. This
will allow any alarms or control signals that
would normally act on the HMV to act on the
P3 instead. Be cautious. Without the HMV,
there is no positive shut off in the off cycle,
and thermal siphoning could occur easily.
Anti-thermal siphoning steps will be crucial.
Figure 18 –No Heat Medium Bypass Valve
COOLING TOWER FAN CONTROL
The unit logic can control the cooling
tower fan if necessary. It is a simple On-Off
control scheme, but it is better than nothing
at all, provided the cooling tower fan in use
can handle being cycled in that fashion.
This control scheme should not be
considered superior to other methods of
cooling water temperature control such as
VFD fans, etc. and should not be used in
conjunction with any other method of cooling
water temperature control.

19
When the CTI sensor indicates the
cooling water inlet temperature to be above
84.2°F (29°C), the unit logic will close the
factory-supplied dry contacts that will allow
the voltage provided to terminal CM1 to be
output to terminal CTF.
When the CTI sensor indicates the
cooling water inlet temperature has fallen
below 80.6°F (27°C), the unit logic will open
the CTF dry contacts.
PUMP SAFETY INTERLOCKS
Each chiller/chiller-heater has a set of
terminals located at the bottom-right of the
control panel labeled 3, 4, 5, 6, and CM2.
These are used as pump safety interlocks
and MUST be connected in order for the unit
to run. If even one of these connections is
missing or electrically open, the unit will lock
out immediately in alarm condition. Such a
lock out is a Manual Reset event.
Figure 19 –Pump/Motor Safety Interlocks
The safety interlock circuit is intended to
be routed through a set of auxiliary contacts
attached to the appropriate pump/motor
starter overload. They should NOT be
connected to auxiliary contacts of the starter
contactor itself or else the unit will lock out
every time the pump shuts down.
Most starter packages in the USA no
longer have auxiliary contacts available even
as options and very few pumps have internal
dry contact thermostats imbedded in the
windings either. However, with the advent of
VFD pump/motor controllers, the availability
of an alarm circuit allows the interlocks to be
wired to the Normally Closed set of alarm
contacts.
If no method of pump safety interlock is
available at all and/or the safety interlocks
are to be jumped, it is highly recommended
that the optional FS2 flow switch be installed
in the cooling water circuit. The FS1 flow
switch for the chilled/hot water circuit is a
standard equipment item with all Yazaki
chillers/chiller-heaters. The installation
instructions for the FS2 flow switch are
included in the accessory package.
BUILDING MANAGEMENT SYSTEMS
The chiller/chiller-heater can be controlled
by Building Management Systems (BMS) or
other remote devices by using field-supplied
SPDT relays, as shown below. Only a
simple Enable/Disable command and a
Heat/Cool command are available. Please
be aware, temperature set points cannot be
set remotely.
Figure 20 –BMS Connections
1. The chiller/chiller-heater itself provides
voltage on terminal E.
2. If the voltage from terminal E is routed back
to terminal A, the unit will engage Cool
mode.
3. If the voltage from terminal E is routed back
to terminal B, the unit will engage Heat
mode.
4. If the voltage from terminal E is routed back
to terminal C, the unit will be Enabled
5. If the voltage from terminal E is routed back
to terminal D, the unit will be Disabled.

20
The rocker switch on the front of the
Control Panel must be set to “REMOTE” in
order for the unit to be controlled by the BMS
in this manner.
It is recommended that field-supplied
SPDT relays be used to prevent conflicting
signals. The wiring diagram designates the
relay controlling Cool/Heat as ESC and the
relay controlling Enable/Disable as ESON. If
a WFC-SC model chiller is being wired to a
BMS, then there is no heat mode available,
therefore, the ESC relay is not needed.
Be aware that if the unit receives the
voltage from terminal E back on both
terminals A and B at the same time or on
terminals C and D at the same time, the unit
will be receiving conflicting commands. The
unit the unit will attempt to satisfy the
commands by switching back and forth
between the two conflicting commands until
the conflict is resolved.
REMOTE MONITORING
There are two optional methods of remote
monitoring. The first is by use of the LON
Adapter and the second is by use of the
Arotrend Remote Monitoring package. It is
possible to use both options at the same
time on the same unit.
The optional LON Adapter accessory will
allow the direct interface of the supported
output data from the Yazaki controls to any
LON-compatible control system. It mainly
provides output data. The only input allowed
is the Enable/Disable signal.
Figure 21 –Arotrend and LON Adapter
Connections in the Junction Box
The LON Adapter installation and wiring
instructions are included with the accessory
package. The LON Adapter is a field-
installed option, though it could be factory-
installed on the WFC-SC50 if ordered as
such.
The available output data from the LON
Adapter is as follows: Alarm condition (with
2-digit error code number), Enable/Disable
mode feedback (is the unit Enabled or
Disabled), Mode feedback (is the unit in Heat or
Cool mode), Operation feedback (is the unit
operating or in standby mode), the entering and
leaving cooling water temperature (CTI and
CTO thermister reading), and leaving
chilled/hot water temperature (WTO thermister
reading). At the time of this writing, no other
data is available through the LON Adapter.
If the LON Adapter is not suitable for use
with the BMS in place, a number of feedback
dry contacts are available in the Junction
Box that can be used to provide information
to the BMS. Consult the Controls Wiring
Diagram in the wiring section for further
details.
A second method of remote monitoring is
the use of the Arotrend Remote Monitoring
package. The Arotrend can connect the unit
to a Yazaki-monitored server or to a
computer that has the proper software
installed. Contact Yazaki Energy Systems,
Inc., for more information on the software
and monitoring services offered as these
options can change or be discontinued
without notification at any time.
The Arotrend Remote Monitoring package
wires to terminals 1 and 2 in the Junction
Box (see Figure 21). The Arotrend package
can report much more data than the LON
Adapter can provide, including temperatures.
It is permitted to use both the LON Adapter
and the Arotrend at the same time.
Finally, Arotrend remote monitoring can
do nothing except monitor. There is no
ability for any input commands through the
Arotrend.
It is not possible in any way to remotely
adjust the leaving water temperature set
points.