Yazaki Aroace WFC-SC10 User manual

WATER FIRED SINGLE-EFFECT
ABSORPTION CHILLER AND CHILLER-HEATER
This product is a water fired absorption unit which provides chilled water for cooling or hot water
for heating in central plant type air conditioning systems. Units with nominal refrigeration
capacities of 10, 20, and 30 tons are complete with operating and safety controls. The absorp-
tion chiller or chiller-heater is energized by heat medium (hot water) at 158oF to 203oF from a
process, cogeneration, solar or other waste heat source.
CONTENTS
INSTALLATION INSTRUCTIONS
WFC-SC10, 20, 30
WFC-SH10, 20, 30
GENERAL Page
•STANDARD SPECIFICATIONS 2
•PHYSICAL DATA 3
•3SEIROSSECCA
•MODEL DESIGNATION 3
•CONTROL ADJUSTMENTS 3
•EQUIPMENT DIMENSIONS 4
•TYPICAL SYSTEM DESIGN 6
•INTERNAL WIRING 8
INSTALLATION
•01GNIVIECER
Page
•UNIT NAMEPLATE 10
•01GNIGGIR
•01NOITACOL
•21NOITADNUOF
•21TNEMECALP
•21GNIPIP
•51LACIRTCELE
•WATER QUALITY 24
•INSTALLATION CHECK AND
REQUEST FOR START-UP 24

GENERAL
STANDARD SPECIFICATIONS
03HS03CS02HS02CS01HS01CSCFWLEDOM
Cooling Capacity (Btu/hr x 1000) 120.0 240.0 360.0
Heating Capacity (Btu/hr x 1000) 166.3 332.6 498.9
Outlet Temperature (oF) Cooling 44.6, Heating 131.0
Rated Water Flow (gpm) 24.2 48.4 72.6
Evaporator Press. Drop (psi) 8.1 9.6 10.1
3.58)isp(.sserPgnitarepO.xaM
Water Retention Volume (gal) 4.5 12.4 19.3
Heat Rejection (Btu/hr x 1000) 291.4 582.8 874.2
Inlet Temperature (o)dradnatS(8.78)F
Rated Water Flow (gpm) 80.8 161.7 242.5
Cond./Abs. Press. Drop (psi) 12.3 6.6 6.7
3.58)isp(.sserPgnitarepO.xaM
Water Retention Volume (gal) 17.4 33.0 51.3
Input (Btu/hr x 1000) 171.4 342.8 514.2
Inlet Temperature (oF) 190.4 (Standard)
Temperature Range 158 (min.) - 203 (max.)
Rated Water Flow (gpm) 38.0 76.1 114.1
Generator Press. Drop (psi) 13.1 6.7 8.8
3.58)isp(.sserPgnitarepO.xaM
Water Retention Volume (gal) 5.5 14.3 22.2
Electrical hp3,zH06,V802ylppuSrewoP
Consumption (W) 210 260 310
ffO-nOlortnoCyticapaC
2
This equipment should only be installed by
trained and qualified personnel who are familiar
with absorption chillers. All precautions in these
instructions, on tags and labels attached to the
unit, must be observed to ensure the safety of
personnel and warranty validation.
Each absorption chiller and chiller-heater has
been evacuated, charged with lithium bromide-water
solution and tested prior to leaving the factory.
Field wiring connections are located on the
left side and piping connections are located on
the rear of each unit.
After the equipment has been installed an
Authorized Yazaki Service Provider will check the
installation and supervise the initial start-up and
operation of the absorption unit.
CAUTION
THE YAZAKI WARRANTY WILL BE
VOIDED IF THE FOLLOWING
RESTRICTIONS ARE NOT OBSERVED:
1. DO NOT OPEN ANY SERVICE VALVES
BECAUSE SUCH ACTION WILL RESULT IN
LOSS OF VACUUM.
2. ALWAYS HANDLE THE EQUIPMENT WITH
CARE AND MAINTAIN IN A NEAR VERTICAL
POSITION DURING RIGGING. IF THE
EQUIPMENT MUST BE TILTED, NOTIFY
THE AUTHORIZED YAZAKI SERVICE
PROVIDER FOR INSTRUCTIONS.
3. DO NOT ATTEMPT TO START THE
ABSORPTION CHILLER WITHOUT SUPER-
VISION FROM THE AUTHORIZED YAZAKI
SERVICE PROVIDER.
Chilled/
Hot
Water
Cooling
Water
Heat
Medium

PHYSICAL DATA
03HS03CS02HS02CS01HS01CSCFWLEDOM
3.457.149.92)ni(htdiW
0.362.152.83)ni(htpeD
Height [Note] (in) 74.8 [75.6] 79.1 [79.9] 80.5 [81.3]
Chilled/Hot Water (in) 1-1/2 NPT 2 NPT 2 NPT
Cooling Water (in) 2 NPT 2 NPT 2-1/2 NPT
Heat Medium (in) 1-1/2 NPT 2 NPT 2-1/2 NPT
002,3050,2001,1)bl(yrD
Operating (lb) 1,329 2,548 3,975
foorprehtaeWepyT
leetsdezinavlagdeppidtohdetniap-erPlairetaM
cillatemrevliShsiniF
Note: Dimensions in [ ] include leveling plate.
ACCESSORIES
Standard Eye Bolts (4), Shims (6), Fuses (4), Installation Instructions (1) and Operating
Instructions (1)
MODEL DESIGNATION
WFC -
Water Fired Single-Effect Absorption Chiller/Chiller-Heater
Model Selection: SC...Chiller, SH...Chiller-Heater
Cooling Capacity: 10...10RT, 20...20RT, 30...30RT
CONTROL ADJUSTMENTS
3
Dimensions
Piping
Weight
Cabinet
•Standard Rating Point Standard Control Settings
The leaving chilled water and hot water
temperature controls are set at the factory to the
Standard Specifications. The Authorized Yazaki
Service Provider can adjust the setpoints with
the ACT-3 maintenance checker to
accommodate step control on multiple units or
satisfy alternative design temperatures,
however, the differential is fixed. Standard
factory setpoints are adjustable from 59.9oF to
41.9oF (leaving chilled water) and 122.9oF to
140.9oF (leaving hot water).

EQUIPMENT DIMENSIONS
WFC-SC10/SH10
WFC-SC20/SH20
Top
Rear
Front View
Left Side
44.9
51.2
41.7
5.9 42.5
79.1
0.8
23.3 34.3
29.8
40.0
4.5 4.532.3
16.7
23.0
20.9
Heat Medium
Outlet
2 NPT
Heat Medium
Inlet
2 NPT
Chilled/Hot Water
Outlet
2 NPT
Chilled/Hot
Water Inlet
2 NPT
Cooling Water
Condenser Inlet 2 Npt
Cooling Water
Condenser Outlet
2 NPT (3C)
Cooling Water Absorber
Outlet
2 NPT
Cooling Water
Absorber Inlet
2 NPT (3C)
10.4
Note: Cooling Water Crossover Pipe Field Connectons Shown In ( ) Are 3" Sweat
Type L Copper.
10.8 10.0
12.0
16.4
6.1 9.0
11.0
37.8
3.5
38.6
7.9
20.8
Cooling Water
Crossover (Optional)
4 Eye Bolts For
Lifting
Mounting
Plate
Field Wiring
Junction Box
19.1
4
TOP
3.5
Field Wiring
Junction Box
31.5
4.9
26.4
29.9
33.1
26.4
4 Eye Bolts For Lifting
Mounting Plate
7.5
38.2
LEFT
FRONT REAR
0.8 74.8
9.0
6.1
12.5
16.4
Cooling Water
Outlet 2 NPT
Cooling Water
Inlet 2 NPT
Heat Medium Outlet
1-1/2 NPT
Heat Medium Inlet
1-1/2 NPT
Chilled/Hot Water Outlet
1-1/2 NPT
Chilled/Hot Water Inlet
1-1/2 NPT
18.4
8.7
20.8
19.5
20.1 45.3
3.3 22.8 3.3
Note: Cooling Water Crossover Pipe Field Connections
Shown In ( ) Are 3" Sweat Type L Copper.
Heat Medium
Outlet
2 NPT
Heat Medium
Inlet
2 NPT
Chilled/Hot
Water Outlet
2 NPT
Chilled/Hot
Water Inlet
2 NPT
Cooling Water
Condenser Outlet
2 NPT (3C)
Cooling Water
Condenser Inlet
2 NPT
Cooling Water
Absorber Outlet
2 NPT
Cooling Water
Absorber Inlet
2 NPT (3C)
Field Wiring
Junction Box
TOP
REARFRONT
LEFT
Cooling Water
Crossover (By others)
4 Eye Bolts
For Lifting
Mounting
Plate

Top View
Rear View
Front View
Left Side
49.6
63.0
54.3
55.1
0.8 80.5
5.3
30.7
35.4
37.3
17.3
19.7
23.1
12.5 10.0
12.3
9.06.1
16.4
57.5
Cooling Water
Crossover (Optional)
3.5
22.5
11.7
50.4
5.5
7.9
4 Eye Bolts For
Lifting
Mounting
Plate
Field Wiring
Junction Box
43.3
5.3
10.6
22.4
Chilled/Hot Water Inlet
2 NPT
Chilled/Hot Water Outlet
2 NPT
Heat Medium
Inlet
2-1/2 NPT
Heat Medium
Outlet
2-1/2 NPT
Cooling Water
Condenser
Outlet
2-1/2 NPT (3C)
Cooling Water
Condenser Inlet
2-1/2 NPT
Cooling Water
Absorber Outlet
2-1/2 NPT
Cooling Water
Absorber Inlet
2-1/2 NPT (3C)
Note: Cooling Water Crossover Pipe Field Connections Shown In ( ) Are 3" Sweat
Type L Copper.
14.8
5
EQUIPMENT DIMENSIONS
WFC-SC30/SH30
All dimensions shown in inches.
Note: Cooling Water Crossover Pipe Field Connections
Shown In ( ) Are 3" Sweat Type L Copper.
Heat Medium
Outlet
2-1/2 NPT
Heat Medium
Inlet
2-1/2 NPT
Chilled/Hot
Water Outlet
2 NPT
Chilled/Hot
Water Inlet
2 NPT
Cooling Water
Condenser Outlet
2-1/2 NPT (3C)
Cooling Water
Condenser Inlet
2-1/2 NPT
Cooling Water
Absorber Outlet
2-1/2 NPT
Cooling Water
Absorber Inlet
2-1/2 NPT (3C)
TOP
REARFRONT
LEFT
Mounting
Plate
4 Eye Bolts
For Lifting
Field Wiring
Junction Box
Cooling Water
Crossover (By others)

TYPICAL SYSTEM DESIGN
(SINGLE MODULE)
WFC-SC10/SH10
WFC-SC20/SH20
WFC-SC30/SH30
6

TYPICAL SYSTEM DESIGN
(MULTIPLE MODULES)
2 X MODULES
(WFC-SC20/SH20, WFC-SC30/SH30)
7

TERMINALS
SYMBOL LOCATION REMARK
Control box
Junction box Field wiring
connections
Control box (I/O board)
Connector
8
INTERNAL WIRING
FUSE RATING
SYMBOL AMPS (A) REPLACEMENT
Bussmann model
F2 3 GLQ-3 or GMQ-3.2,
rated 300 V AC
F11, F12 2 Fuji model FGAO-2,
F4 2 rated 250 V AC
FT1, FT2 5
SOLUTION PUMP OVERLOAD SETTINGS
SYMBOL WFC MODEL (*208 V AC)
SC/SH10 SC/SH20 SC/SH30
THRP 0.4 0.7 2.0
* Power supply tolerance +10%, -5%
L1
L2
L3
G
L1
L2
L3
G
SP
U V W MP
2
SV9
3
FT2 TR5
WFC-TRUL1
TR2
FT1 TR4
F11
F12
TR7
TR8
OV 24V
AC
A1
208V A2 TR1
THRP
MP
208V, 60Hz, 3PH
POWER SUPPLY
JUNCTION
BOX
G
G
SA1
RMP RV9
CN12
*
CVR
1 2 6 3 4
1 2 3 6
1 2
54
5 CM2 CTF CM1 P
P3A
P3B
A B C D E
A B C D E
F G H
H
L
C
L
C
M
3
C
H
O
F
F
C
H
O
N
H
1
C
1
C
P
P P
3
A
P
3
B
C
M
1
C
M
2
F
D
P
1
D
P
2
D
P
3
D
C
T
F
O
P
L
L
C
O
M
E
D
M
H
M
C
M
C
O
M
E
S
O
F
F
E
S
O
N
E
S
H
1
E
S
C
1
L
C
O
M
I
IOCN1
IOCN2
TMC1
CPU
CPU
CPU
S3
EGBON HM CM CHD CHE
S4 S5 S6 S7 S8 S11 S12 S13 S14
S3 S4 S5 S6 S7 S8 S11 S12 S13 S14
CP
TB2
CN-16
LTPV
CIRCUIT
LTVP
FE
P2EP1ECIRHIRIRSLS AC24VDCPST2IF1IF2
MGC2-4
OUC-5
TB2
TB4
TB1
CHE
1F3
EGON
EGON
P3D
P3D
MGC2
EXF
RFH
(MF)
EGBON
(RBL)
RCVR
RBPW
SV9OPSP
AC
24V
AC
24V
AC18V
TR-LV
TR9TR11
TR10
F2
F4
SA2
A1 A2
AC15V
MONITORING
UNIT
DC POWER
JUNCTION BOX
I/O BOARD
P2P1
FS1
FS2
CN11
NC
Tr
1 28 9 3 125410 11
5131411 721 6 8 12 9104 11
9 710 8 4 5 6 31 211 912 10 6 3 4 1 2 13 1457 8
CNC2-1
CNPV
5 6 3 4 1 2
1 4 1 3 2 4
RP3
HM
CHSTN
CM OP CHD AL
T B3
(MS)
OUC2-G TMC2-2
(GSPS)
17
1847351
1
387124 1
3715421
14543
HC
26
C
O
N
H
O
N
20723
11
8372543
2
3
6
1
4
1
2
3
4
615181
116 1 3 6
12 3 5 4
8
2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20
3 1 2
18
THRP
RFH
S14S13S12S11S8S7
S10
BO
S9
S6S5S3
SV1
SV10
CNC2-2
BPC
S4
S1 S2
SV11SV1
RBO
RP3 RV9 EGS GPSC
GPSH
RMP
CNC-1
CN13
CN13
CN12
MGC-1
G
Only installed on SH model chiller-heaters.
TRC3
TRC1 TRC2
OUC-4
PWC
CH
**
R
B
O

OPTIONAL I/O BOARD CONNECTIONS
TERMINAL DESCRIPTION REMARKS
TB No.
INTERNAL WIRING
SYMBOL DESCRIPTION REMARK
0
OPTIONAL JUNCTION BOX CONNECTIONS
TERMINAL DESCRIPTION REMARKS
1, 2 (DCP) Remote monitoring
A (C1) Cooling mode selection Remote
B (H1) Heating mode selection selection of
C (CHON) Start selection COOL, HEAT,
D (CHOFF) Stop selection ON, OFF
E (CM3) Common 3
CTF
Cooling tower fan
control (84.2oF ON,
80.6oF OFF)
S11, S12
e
(CHD)
(CHE) alarm
9
STANDARD JUNCTION BOX CONNECTIONS
TERMINAL DESCRIPTION REMARKS
3 (P1D/P1E)
Chilled/hot water pump
thermal overload
4 (P2D/P2E) Cooling water pump Interlocks
thermal overload (NC or NO)
5 (FD/FE) Cooling tower fan for thermal
thermal overload overload trip
Heat medium pump contacts
6 (P3D/P3E) thermal overload or
heat medium bypass
valve limit switch
CM1 Common 1
S3, S4 Heat medium pump
( )NOBGE
1
MG
C2
3
7,8
(ST2)
9,10
(IF1)
3,7
(IF3)
7,8
(CHSTN)
13,14
(OP)
17,18
(AL)
Shutdown interlock
Chilled/hot water
freeze protection
Heat medium
freeze protection
Chiller-heater
standby mode
Operating status
General fault alarm
Additional
interlock
(NC or NO)
Input control
from temp.
switch
(36.5°F ON,
39.2°F OFF)
OPTIONAL CONTROL BOX CONNECTIONS
TERMINAL DESCRIPTION REMARKS
S1, S2 Heat medium supply
(RFH) shutdown
S9, S10 Auxiliary boiler
(BO)
Chiller Enabled
CP (P2) Cooling water pump
P3A Heat medium pump or
heat medium bypass
P3B valve
P (P1) Chilled/hot water pump
17, 18 Input
(EGON) Heat available control from
temp. switch
2, 3 on Cooling water Input control
CN11 (FS2) flow switch from flow
switch
S5, S6
(HM) Heating mode
S7, S8
(CM) Cooling mode
SP Solution pump
MP Solution pump
motor contactor
THRP Solution pump
thermal overload
CVR Changeover valve
SH model only
WFC-TRUL1 Class 2 transformer 208/24V AC
TR-LV Low voltage 24/18,
transformer 16 V AC
SA1, SA2 Surge absorbers
F2, F4,
F11, F12
FT1, FT2 Fuses
Refer to
Fuse Rating
Table
SV1 Refrigerant freeze
protection valve
SV9 Concentrated solution
bypass valve
SV11 Refrigerant drain valve
SH model only
LTPV Refrigerant proportional
control valve
LT Evaporator
temperature sensor
WTO Chilled/hot water
temperature sensor
CTI Cooling water
temperature sensor
HWT Heat medium
temperature sensor
FS1 Chilled/hot water
flow switch
RMP, RP3, Control relays
RV9, RB0

RECEIVING
When the absorption chiller is delivered to
the job site, inspect for any transit damage. Report
any damage to the carrier and note on the bill of
lading. Notify the Yazaki Sales Representative or
Distributor before proceeding with the installation
of a damaged unit.
UNIT NAMEPLATE
The UNIT NAMEPLATE is located on the
lower right hand side of the front panel on each
absorption chiller unit. Check that the model
number, flow rates and electrical specifications
are compatible with the system design and
services available.
RIGGING
Remove the crate from the absorption chiller.
When access is restricted, it may be necessary to
remove the skid to reduce overall height.
Each unit has four eye bolts in the top panel
which should be used for lifting.
Care should be taken at all times during
rigging and handling of the absorption chiller to
avoid damage to the panels and external pipe
connections. DO NOT DROP.
Attach a sling to the four eye bolts in the top
panel as shown in Fig.1 and ensure that the rope
angle is greater than 60Oto the horizontal plane.
Always carry the absorption chiller in a NEAR
VERTICAL POSITION. DO NOT TIP OVER.
The dry weight and overall dimensions are
shown in PHYSICAL DATA on Page 3 as a guide
for rigging (add 6 in. to overall height for skid).
When moving the absorption chiller, check
that the route is accessible. The minimum access
dimensions for a skid mounted chiller are shown
in Fig.2.
LOCATION
Yazaki absorption chillers have a weather-
proof cabinet suitable for either indoor or outdoor
installation.
Select a location with due consideration for
the proximity of the cooling tower, chilled/hot
water coils and service access.
The minimum space requirements, shown in
Fig.3, must be provided around and above each
chiller for installation and service access.
Fig. 1 RIGGING
MODEL
DIMENSION WFC-SC10 WFC-SC20 WFC-SC30
WFC-SH10 WFC-SH20 WFC-SH30
A93 98 98
B63 75 88
C63 75 88
D63 75 88
Fig. 2 ACCESS CLEARANCES (IN.)
The roof on which equipment is to be
installed shall be capable of supporting the
operating weight of the absorption chiller,
associated pumps, cooling tower and piping.
Install the equipment on a well drained surface of
the roof at least 6 ft. from the edge. If the roof is
poorly drained at the equipment or in the
passageway to the equipment a suitable platform
of walkway should be provided adjacent to the
equipment and control panels so that it can be
serviced safely.
10
INSTALLATION

C 29.9
49.9
B
10.0
E
33.1
38.2 DF
A
26.4 46.2
7.5
4.0
Mounting
Plate
51.2
61.9
10.0
59.2
4.0
41.9
44.9
51.2
71.0
71.0
61.9
10.0
54.3
57.5
Mounting
Plate
74.3
10.0
59.2
4.0
9.14C
44.9
Mounting
Plate
Mounting
Plate
10.0
59.2 51.2
A
DF
38.67.9
131.8
10.0
59.2
41.9 E
44.9
B
B
28.0
4.0
38.67.9
63.0 50.47.9
4.0
63.0 50.4
7.9
FRONT
WFC-SC30/SH30
54.3
57.5
10.0
FRONT
WFC-SC30/SH30
54.3
57.5
FRONT
WFC-SC30/SH30
FRONT
WFC-SC20/SH20
FRONT
WFC-SC20/SH20
A
C
FRONT
WFC-SC20/SH20
FRONT
WFC-SC10/SH10
D
E
F
Mounting
Plate
Fig. 3 INSTALLATION CLEARANCES (IN.)
11
INSTALLATION AREA
MODEL DIM. (IN)
No. WFC A B
1 SC10/SH10 118.2 85.9
1 SC20/SH20 131.2 97.9
1 SC30/SH30 143.0 110.3
2 SC20/SH20 131.2 167.8
2 SC30/SH30 143.0 192.6
SERVICE CLEARANCE
SIDE DIMENSION (IN)
LEFT (C) 28
REAR (D) 40
RIGHT (E) 28
FRONT (F) 40
ANCHOR BOLT DETAIL
SHIM DETAIL
2.8
3.1
1.2
Cabinet
Shim
WFC
Nut And Washer
Anchor Bolt (1/2")
Mounting Plate
Material: 304SS
Thickness 2mm
1.6
5.9
3.1
Foundation
Installation Area
Foundation
Installation Area

12
FOUNDATION
Mount the absorption chiller on a level floor or
foundation capable of supporting the operating
weight of the unit (refer to PHYSICAL DATA on
Page 3).
A concrete base, with dimensions shown in
Fig. 4, should be at least 12 in. thick and
reinforced with crushed rock or steel.
PLACEMENT
When the absorption chiller has been moved
into final position, remove the skid (if not already
removed). Place a spirit level on the level bar,
shown in Fig. 5, and insert stainless steel slotted
PIPING
GENERAL
After leveling the absorption chiller, the piping
for chilled/hot water, cooling water and heat
medium should be installed. Arrange the piping
with offsets so that it does not interfere with
removal of panels or service access to the
equipment. Adequately support and brace the
piping independently of the unit to avoid strain on
the pipe connections. Provide thermowells at each
inlet and outlet connection for measurement of
fluid temperatures during start-up and routine
maintenance (not required on cooling water
crossover piping).
CHILLED/HOT WATER PIPING
The chilled/hot water piping contains chilled
water during cooling operation and hot water
during heating operation and must be
adjustment plates (shims) between each
mounting plate and the foundation, as shown in
Fig. 6. Adjust the shim thickness for longitudinal
and transverse alignment of the absorption chiller.
pressurized, as shown in Fig. 7, by either an open
cistern or closed expansion tank. Install piping
with a rising grade of 1/200 and install manual
vent valves at high points to expel trapped air.
A balancing valve should be installed
adjacent to the chilled/hot water outlet on each
unit to facilitate flow rate adjustments within
specified limits. Install a stop valve adjacent to the
chilled/hot water inlet on each chiller. This valve
must be in the full open position when the
equipment is operating. DO NOT CLOSE the stop
valve except for disconnection or relocation of the
machine.
Insulate piping AFTER LEAK TESTING to
prevent heat transfer and sweating. Cover
insulation with a vapor barrier and ensure all stop
valves, balancing valves and thermowells are
accessible.
Fig. 4 FOUNDATION EXAMPLE
Fig. 5 LEVEL BAR Fig. 6 ADJUSTMENT (SHIM) PLATE

Whenever the absorption chiller or the
chilled/hot water piping is installed outdoors and
subject to ambient temperatures below freezing,
the circuit should be filled with a glycol solution of
adequate concentration to prevent freezing. It is
important that the glycol solution contain
inhibitors to protect the copper tubes in the
absorption chiller from corrosion. If glycol is not
used for freeze protection, install a temperature
limit switch in the lowest outdoor section of the
HEAT MEDIUM PIPING
The heat medium piping contains water which
must be pressurized, as shown in Fig. 8, by either
an open cistern or closed expansion tank. Install
piping with a rising grade of 1/200 and install man-
ual vent valves at high points to expel trapped air.
A balancing valve should be installed adja-
cent to the heat medium outlet on each unit to
facilitate flow rate adjustments within specified
limits. Install a stop valve adjacent to the heat
medium inlet on each chiller. This valve must be in
the full open position when the equipment is
operating. DO NOT CLOSE the stop valve except
for disconnection or relocation of the machine.
Insulate piping AFTER LEAK TESTING to
prevent heat loss and ensure that all stop valves,
balancing valves and thermowells are accessible.
Whenever the absorption chiller or the heat
medium piping is installed outdoors and subject
to ambient temperatures below freezing, the
chilled/hot water pipe and interlock the switch with
the absorption chiller controls (refer to Optional
Field Wiring Connections).
circuit should be filled with a glycol solution of
adequate concentration to prevent freezing. It is
important that the glycol solution contain
inhibitors to protect the stainless steel tubes in
the absorption chiller from corrosion. If glycol is
not used for freeze protection, install a
temperature limit switch in the lowest outdoor
section of the heat medium pipe and interlock the
switch with the absorption chiller controls (refer to
Optional Field Wiring Connections).
Install a motorized 3-way bypass valve (HMV)
with limit switches to control the heat input to the
absorption chiller.
Fig. 8 HEAT MEDIUM PIPING
13
CAUTION
1. DO NOT EXCEED 80 - 120% OF
STANDARD CHILLED/HOT WATER FLOW.
2. DO NOT EXCEED 85.3 PSI IN THE
CHILLED/HOT WATER CIRCUIT AT THE
ABSORPTION CHILLER.
3. DO NOT INSTALL ANY VALVES IN THE
EXPANSION LINE.
CAUTION
1. DO NOT EXCEED 30 - 120% OF
STANDARD HEAT MEDIUM FLOW.
2. DO NOT EXCEED 85.3 PSI IN THE
HEAT MEDIUM CIRCUIT AT THE
ABSORPTION CHILLER.
3. DO NOT INSTALL ANY VALVES IN THE
EXPANSION LINE.
Heat Medium
Outlet
Heat Medium
Inlet
T
Drain
IF3 Switch (Optional)
Heat Medium Pump
Air Vent
Chiller/Chiller - Heater
T
Water Make-Up/
Expansion Line
Check/Reducing Valve
Expansion Tank
Relief Valve
Water Supply
Heat Medium Bypass Valve (HMV)
PP
Fig. 7 CHILLED/HOT WATER PIPING
T
T
Chilled/Hot Water Pump
IF1 Switch (Optional)
Air Vent
Drain
Water Supply
Check/Reducing Valve
Expansion Tank
Relief Valve
Water Make-Up/
Expansion Line
Chilled/Hot Water
Outlet
Chilled/Hot Water
Inlet
Chiller/Chiller - Heater
PP

14
COOLING WATER PIPING
Heat from the absorption chiller is rejected to
a well, river or cooling tower and cooling water is
maintained at 85OF or less during the cooling
season. Provide drain valves at all low points in
the piping so that the circuit can be drained
during the winter and for maintenance.
All 20 and 30 ton absorption chillers (Models
WFC-SC20, WFC-SH20, WFC-SC30 and WFC-
SH30) require cooling water crossover piping to
connect the condenser and absorber in parallel.
Install crossover piping, in accordance with Fig.
9, to ensure balanced cooling water flow through
the condenser and absorber. If the crossover
design is changed, install balancing valves at the
condenser outlet and absorber outlet connections
so that the flow rate through each circuit can be
adjusted in accordance with the chiller
specifications. As an alternative, install the
optional Yazaki cooling water crossover pipe
assemblies.
A balancing valve should be installed
adjacent to the cooling water outlet on each
absorption chiller to facilitate flow rate
adjustments within specified limits. Install a stop
valve adjacent to the cooling water inlet as shown
in Fig. 9. This valve must be in the full open
position when the equipment is operating. DO NOT
CLOSE the stop valve except for disconnection or
relocation of the absorption chiller unit.
If the cooling water inlet temperature is below
65OF and likely to remain at this condition after
the first 30 minutes of cooling operation, a
cooling water temperature control system, as
shown in Fig. 10 must be installed. The
motorized 3-way valve (CWV) will bypass cooling
water to the sump whenever the cooling water
inlet temperature is below 65OF.
Wherever possible, install the cooling tower
at the same level or above the absorption chiller.
If this cannot be accomplished, give careful
consideration to the piping design to avoid
overflowing the cooling tower sump every time
the cooling water pump stops.
If cooling water remains in the condenser and
absorber section of the chiller-heater during
heating operation, and the unit is immediately
switched to cooling mode, a slug of hot water
NOTES:
1. Each standard crossover pipe has similar
pressure losses for balanced cooling water
flow through the absorber and condenser.
2. Install flow balancing valves in each circuit for
non-standard crossover pipe designs.
3. Install cooling water flow valves 5 pipe
diameters (min.) upstream and downstream
of the respective “T” fitting.
4. The crossover pipe configuration must
provide clear access to the rear of the
absorption chiller for maintenance.
Fig. 9 COOLING WATER CROSSOVER PIPING
Fig. 10 COOLING WATER PIPING
CAUTION
1. DO NOT EXCEED 100 - 120% OF
STANDARD COOLING WATER FLOW.
2. DO NOT EXCEED 85.3 PSI IN THE
COOLING WATER CIRCUIT AT THE
ABSORPTION CHILLER.
Balancing
Valve
Stop Valve
3" Cu Tube
3" Cu Tube
Cooling Water
Condenser Outlet
Cooling Water
Absorber Outlet
Cooling Water
Condenser Inlet
Cooling Water
Absorber Inlet
2" Cu Tube (WFC-SC20/SH20)
2 1/2" Cu Tube (WFC-SC30/SH30)
Note 3
Note 3
Union (CxM)
Cooling Water
Outlet
Cooling Water
Inlet
Chiller/Chiller - Heater
Condenser Water
Inlet
Absorber Water
Outlet
Cooling Tower
T
Drain
Cooling Water Pump
Flush
Valve
Flush
Valve
T
Temp. Control (CWTS)
Cooling Water Control
Valve (CWV)
Drain
Water Supply
Crossover Piping
For WFC-SC20/SH20 &
WFC-SC30/SH30 ONLY
PP

15
above 120OF may damage the cooling tower fill
material at the start of cooling operation. This
problem can be prevented by overriding the
motorized 3-way valve (CWV) to bypass cooling
water to the sump for at least 1 minute each time
cooling operation is selected or by utilizing a high
temperature fill material in the cooling tower. In
an extended heating season the cooling water
ELECTRICAL
GENERAL
Each absorption chiller and chiller-heater is
factory wired for the voltage specified on the
UNIT NAMEPLATE. The standard field wiring con-
nections are provided in the junction box
located on the left side of each unit.
Optional field wiring connections for
accessories and alarms are provided in the
should be drained from the chiller-heater.
When the cooling water circuit is not drained
but is subject to ambient temperatures below
freezing, install a heater in the cooling tower sump.
All exposed piping below the water level should be
protected by electric heat tape and insulation.
junction box and control box (terminal strip on I/O
board) of the chiller-heater control box. Refer to
page 9 for further details.
All absorption chillers must be electrically
grounded and field wiring installed in accordance
with the National Electrical Code (NFPA 70,
latest edition).
Option 1: HEAT INPUT CONTROL BY HEAT MEDIUM PUMP AND HEAT MEDIUM BYPASS VALVE
FIELD WIRING DIAGRAM (SINGLE MODULE)
P3A

16
Option 2: HEAT INPUT CONTROL BY HEAT MEDIUM PUMP ONLY
Option 3: HEAT INPUT CONTROL BY HEAT MEDIUM BYPASS VALVE ONLY
OPTIONAL COOLING WATER
TEMPERATURE CONTROL
(With Cooling Water Valve Override)
OPTIONAL COOLING WATER
TEMPERATURE CONTROL
(Without Cooling Water Valve Override)
INTERLOCK CONTACTS (NC)
P3A

EXTERNAL WIRING (SINGLE MODULE)
SYMBOL DESCRIPTION REMARKS
FD2 Cooling water pump
fused disconnect
FDF Cooling tower fan
fused disconnect Supplied
FD3 Heat medium pump by others
fused disconnect
FDV Heat medium bypass
valve fused disconnect
MC1 Chilled/hot water pump
motor contactor
MC2 Cooling water pump
motor contactor Supplied by
MCF Cooling tower others (24V
fan motor contactor AC coil)
MC3 Heat medium pump
motor contactor
THR1 Chilled/hot water pump
thermal overload Supplied by
THR2 Cooling water pump others
thermal overload (1xNC and
THRF Cooling tower fan 1xNO
thermal overload contact)
THR3 Heat medium pump
thermal overload
CTF Cooling tower fan
P3 Heat medium pump
Interlock relays for
R, R3 power supply and
HMV limit switch
RT1, RT2, Interlock relays for
RT3, RTF thermal overloads
RCW, R3W Control relays for CWV
RC3 Control relay for HMV
T3W Timer (1 min. TDO)
for CWV
STANDARD JUNCTION BOX CONNECTIONS
TERMINAL DESCRIPTION REMARKS
3
(P1D/P1E)
Chilled/hot water pump
thermal overload
4 (P2D/P2E)
Cooling water pump
thermal overload
5 (FD/FE) Cooling tower fan
thermal overload
Heat medium pump
6 (P3D/P3E) thermal overload and/or
heat medium bypass
valve limit switch
P (P1) Chilled/hot water pump
17
EXTERNAL WIRING (SINGLE MODULE)
SYMBOL DESCRIPTION REMARKS
FDC Chiller or chiller-heater
fused disconnect
Supplied by
others
Supplied by
others
CHILLER OR CHILLER-HEATER JUNCTION BOX
Six knockouts in bottom of junction box to suit 1/2
in. trade size conduit.
Interlocks
(NC or NO)
for thermal
overload
trip
contacts
S3, S4 Heat medium pump
(EGBON)
CP (P2) Cooling water pump
FD1 Chilled/hot water pump
fused disconnect
P3A Heat medium pump
or heat medium
bypass valve
P3B
Output
control (NO)
Output
control (NC)
CM1 Common 1
P1 Chilled/hot water pump
P2 Cooling water pump
SW1 Chilled/hot water pump
Auto/Manual switch
SW2 Cooling water pump
Auto/Manual switch
SW3 Heat medium pump
Auto/Manual switch
SWF Cooling tower fan
Auto/Manual switch

OPTIONAL JUNCTION BOX CONNECTIONS
TERMINAL DESCRIPTION REMARKS
S11, S12
(CHD)
S5, S6 (HM) Heating mode
S7, S8 (CM) Cooling mode
S13, S14 General shutdown
(CHE) alarm
EXTERNAL WIRING (SINGLE MODULE)
SYMBOL DESCRIPTION REMARKS
CWV Cooling water temp.
control valve (3-way)
Cooling water temp.
CWTS switch (70oF ON,
75oF OFF)
CTS Cooling tower switch
(81.5oF ON, 77oF OFF)
HMV Heat medium bypass
valve (3-way)
3VOP Limit switch for HMV
open position
NOTES:
1. The Heat Medium Pump (P3) and/or Heat
Medium Bypass Valve (HMV) are controlled
by the chiller/chiller-heater in response to the
chilled/hot water outlet temperature. The valve
cycle time must be less than 30 seconds.
2. An optional Cooling Water Temperature
Switch (CWTS) controls the cooling water
inlet temperature by modulating the Cooling
Water Valve (CWV). It is required when the
cooling water inlet temperature is likely to fall
below 65oF during cooling operation in low
ambient weather.
3. A Cooling Tower Switch (CTS), installed in
the cooling tower sump, controls the cooling
water temperature by cycling the cooling
tower fan.
4. A Limit Switch (3VOP), installed on the heat
medium bypass valve, closes when the valve
is open.
5. Optional controls override the Cooling Water
Valve (CWV) to bypass “hot” cooling water to
the cooling tower sump for one minute each
time cooling operation is selected. This
prevents damage to the cooling tower fill
material from “hot” cooling water when it
remains in the chiller-heater during heating
operation.
6.
OPTIONAL JUNCTION BOX CONNECTIONS
TERMINAL DESCRIPTION REMARKS
1, 2 (DCP) Remote monitoring
A (C1) Cooling mode selection
B (H1) Heating mode selection
C (CHON) Start selection
D (CHOFF) Stop selection
E (CM3) Common 3
Cooling tower fan
CTF control (84.2OF ON,
80.6OF OFF)
Remote
selection of
COOL,
HEAT, ON,
OFF
Alternative
to CTS
temp. control
Supplied by
others
OPTIONAL FIELD WIRING CONNECTIONS
18
Supplied by
others (Max. 30
sec. valve cycle
time)
Chiller Enabled
Field wiring shown as a broken line.
7. All circuits except power supply are low
voltage.
8. Confirm that the voltage rating on the chiller
or chiller-heater nameplate is compatible with
the local power supply.
9. All wiring must comply with local and national
electrical codes.

OPTIONAL I/O BOARD CONNECTIONS
TERMINAL DESCRIPTION REMARKS
TB No.
7, 8 Shutdown interlock
Additional
1(ST2) interlock
(NC or NO)
9,10 Chilled/hot water Input control
(IF1) freeze protection from temp.
MG 3, 7 Heat medium switch
C2 (IF3) freeze protection (36.5°F ON,
39.2°F OFF)
7, 8 Chiller-heater
(CHSTN) standby mode
13, 14 Operating status
3(OP)
17, 18 General fault alarm
(AL)
OPTIONAL CONTROL BOX CONNECTIONS
TERMINAL DESCRIPTION REMARKS
S1, S2 Heat medium
(RFH) supply shutdown
S9, S10 Auxiliary boiler
(BO)
17, 18 Input control
(EGON) Heat available from temp.
switch
2, 3 on CN Cooling Water flow Input control
11 (FS2) switch from flow
switch
NOTES:
1. Set switch 1 on DIP switch DP1 (located on
I/O Board) to ON for normally open (NO)
interlock contacts and to OFF for normally
closed (NC) interlock contacts.
2. Field wiring shown as a broken line.
3. All circuits are low voltage.
4. All wiring must comply with local and
national electrical codes.
5. Remove jumpers from terminals when field
wiring installed.
19
7 8

NOTES:
1. Full Load Amps (FLA) marked on motor nameplate.
2. Use minimum 14 AWG copper conductors for absorption chiller power supply.
Table 1 ELECTRICAL DATA
MODEL
WFC-SC10
WFC-SH10
WFC-SC20
WFC-SH20
WFC-SC30
WFC-SH30
POWER
SUPPLY
(V)
208
208
208
SOLUTION PUMP
(3 PH)
OUTPUT FLA
(HP) (A)
1/8 0.46
1/6 0.75
1/3 2.04
POWER SUPPLY
MIN. CIRCUIT AMPS MAX. FUSE SIZE
)A()A(
516.0
519.0
516.2
20
POWER WIRING
Select the disconnect, fuses and supply
conductors for each absorption chiller based on
the minimum circuit ampacity and maximum fuse
size on the UNIT NAMEPLATE as per the
Electrical Data in Table 1. Install conduit to the
field wiring junction box and leave sufficient clear-
ance for removal of panels and service access.
DO NOT attach conduit to the absorption chiller
cabinet. The 1/2 in. trade size conduit entry in the
junction box will accommodate four (3 live and 1
grounded) 14 AWG copper conductors in most
wire styles. DO NOT USE ALUMINUM
CONDUCTORS.
Locate the disconnect within sight of and
readily accessible to the equipment, per Section
440-14 of the National Electrical Code.
DO NOT CLOSE THE DISCONNECT until
approved by an Authorized Yazaki Service
Provider.
CONTROL WIRING
All field control wiring connections to the
absorption chiller are low voltage (less than 30 V
AC) class 2 circuits and may be installed with or
without conduit. A 1/2 in. trade size conduit should
be installed to protect the wire against physical
damage or for aesthetic reasons. If
conduit is not used, a bushing must be inserted
into the wire entries of the junction box. Route
additional wiring to the control box for optional
input and output controls through the absorption
chiller junction box.
Motor contactors and overload relays for the
chilled/hot water pump, cooling water pump, heat
medium pump and cooling tower fan are not
installed in the absorption chiller and must be
supplied by others. Refer to the relevant Field
Wiring Diagram (Single Module or Multiple
Modules) for the recommended wiring of these
controls.
Use 18 AWG type T wire or equivalent for all
low voltage field circuits up to 50 ft. (for longer
distances use a 16 AWG conductor).