Carrier 42C Series Operation manual

Copyright 2004 Carrier Corporation Form 42-2PD
Carrier’s 42C,D,S,V Series fan-coil
units combine design flexibility with
easy, low-cost installation.
Features/Benefits
Versatility
If room fan coils are the answer to your
job requirements, choose from Carrier’s
extensive range of superior fan-coil
units.
With Carrier’s 42 series fan coils, you
can select from 5 horizontal, 6 vertical,
5 ducted or 3 stacked models; furred-in
or cabinet style, slant top or low silhou-
ette, in 150 through 2000 cfm capaci-
ties. Coils are available with 1, 2, 3, 4,
or 5 rows (depending on model), to
satisfy a variety of application require-
ments. The units are ideal for installa-
tion in motels, apartments, and other
multi-room buildings. Many optional
control packages are available, including
2-pipe heating and cooling, 2-pipe
heating and cooling with auxiliary elec-
tric heat, 2-pipe cooling with total elec-
tric heat, and 4-pipe heating and cool-
ing. Also offered are manual and auto-
matic changeover controls and several
thermostat options.
Casings and frame are fabricated from
tough, heavy gage galvanized steel. Op-
tional decorative colors allow the unit to
blend with any interior design.
Low-cost installation and
operation
Each unit is designed to occupy a
minimum space. No complex system
controls are required for Carrier fan coil
units. Piping, drain, and wiring connec-
tions are readily accessible and mount-
ing holes and slots are pre-drilled to
save installation time and field labor
expense.
42C,D,S,V Series
Fan Coil
Air Conditioners
50/60 Hz
150 to 2000 cfm
Product
Data
42CA HORIZONTAL
42DA DUCTED
42VB VERTICAL
42SH STACK

2
42 Series quality reduces
service and maintenance
expenses
Condensate drain pan is heavy gage
galvanized steel with closed-cell, fire re-
tardant foam insulation. Units come
standard with Tuf-Skin™ II insulation
for energy savings, sound absorption
and Indoor Air Quality (IAQ) preserva-
tion. Water never touches the pan, so
corrosion is minimized and long,
trouble-free life is assured.
Efficient operation
All units use permanent split capacitor
motors for minimum electrical con-
sumption. Blower wheels are
centrifugal-type, forward curved,
double width, and double inlet sized
for maximum efficiency.
Quiet, dependable
performance
All units are built to operate unobtru-
sively with quiet motors and fans. In ad-
dition,
1
/
2
-in. thick sound-absorbing,
multi-density, matt faced, neoprene-
coated fiberglass insulation is used to
line the cabinet.
42C series horizontal, 42V
series vertical units
Carrier room fan-coil units operate at
exceptionally low sound levels. A gen-
erous amount of insulation absorbs
operating sound and rugged, rigid con-
struction ensures vibration free opera-
tion at all fan speeds.
Economical, three-speed fans deliver
just the right amount of conditioned air
for your comfort needs at any load,
and each unit can be shut off when not
in use. Permanent split capacitor mo-
tors deliver peak operating efficiency.
By choosing Carrier units, you can
match your application with a wide
range of custom-designed options and
accessories, including electric heat. Fil-
ters are cleanable or throwaway type.
Motor bearings are heavy-duty
sleeve type, with oversize oil reservoirs
to assure long bearing life. All coils are
factory leak-tested at 350 psig mini-
mum air pressure.
Carrier room fan-coil units provide
unsurpassed year-round comfort, with
heating and cooling performance
certified in compliance with ARI (Air
Conditioning & Refrigeration Institute)
440-98.
42D ducted units
A drip lip (removable drain pan exten-
sion) is provided for field installation on
ceiling models 42DA,DC,DE and DF
when a motorized valve package is or-
dered. The drip lip is also available as
an accessory for use with other
controls.
Motor/blower assembly can be easi-
ly removed from the unit for ease of
service. Removing this assembly pro-
vides clear access to the entering air
face of the coil, making coil cleaning a
relatively simple matter. Removable
panels make access to components
and connections easy.
42S stacked units
Each Carrier stack unit comes factory-
equipped with insulated supply, return,
and drain risers. The design of the 42S
units allow them to be set one on top
of the other in a vertical column rising
floor to floor up the building. Each
riser has a 3-in. belled section at
the top, so the riser piping can be
connected by only one sweat connec-
tion per riser. Field-installed couplings
or internal pipe connections are not
needed.
Each stack unit is factory pre-wired
with all control, motor, and optional
electric heat wiring conveniently termi-
nating in a single, accessible junction
box. Each stack unit requires only one
field power connection.
Field-mounted accessories, such as
the 3-speed switch/thermostat pack-
age for furred-in units, are equipped
with a pre-wired quick disconnect plug
for easy installation.
The riser size for the stack units can
be specified to match building require-
ments so that cutting, sorting, and han-
dling of the risers is not necessary. All
units arrive tagged as specified by the
customer for efficient delivery to the
correct building location.
Units can be loaded onto delivery
trucks so that they can be off-loaded in
the proper installation sequence.
Table of contents
Page
Features/Benefits . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-6
Options and Accessories . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .7-9
Controls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10-12
Application Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13-25
Selection Procedure . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 26
42C,V
Model Number Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 27
ARI Capacity Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 28
Sound data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 29,30
Physical Data and Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 31-42
Accessory Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 43-47
Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 48-63
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 64-66
42D
Model Number Nomenclature . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
ARI Capacity Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 67
Sound data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68
Physical Data and Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 68-73
Accessory Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 74-76
Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 77-86
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 87-89
42S
Model Number Nomenclature. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
ARI Capacity Ratings . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 90
Sound data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91
Physical Data and Dimensions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 91-94
Accessory Dimensions. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 95-97
Performance Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 98-103
Electrical Data . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 104
Guide Specifications — 42C Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 105,106
Guide Specifications — 42D Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 107,108
Guide Specifications — 42S Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 109-111
Guide Specifications — 42V Series . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 112,113

3
Features/Benefits (cont)
42CA
Furred-in ceiling model with low silhouette.
(200-1200 cfm)
42CE
Furred-in ceiling model with factory-installed
plenum.
(200-1200 cfm)
42CF
High-static, furred-in model.
(400-1000 cfm)
42CG
Cabinet model for under-ceiling mount with
bottom or rear stamped louver return air grille.
(200-1200 cfm)
42CK
Cabinet model with telescoping flip-down panel
and stamped louver bottom return or duct
collar rear return.
(200-1200 cfm)

4
Features/Benefits (cont)
42VA
Furred-in model for under-the-window
applications with top or front discharge.
(200-1200 cfm)
42VF
Cabinet model with slant top and
top or front discharge.
(200-1200 cfm)
42VC
Furred-in loboy model for concealed under-the-
window applications.
(200-600 cfm)
42VE
Cabinet loboy model with stamped louver dis-
charge grille and 2 control access doors.
(200-600 cfm)
42VG
Furred-in wall model. Available with a 10-in.
valve compartment extension.
(150 and 300 cfm)
42VB
Cabinet model with top or
front discharge.
(200-1200 cfm)

5
42DA
Furred-in model for installation in the
ceiling or over the closet.
42DD
Vertical model with galvanized casing.
Commonly for closet installation.
42DE
Ceiling model with galvanized casing.
42DF
Exposed-ceiling cabinet model with inte-
gral double-deflection discharge grille and
a bar-type return-air grille.
42DC
Furred-in ceiling model with factory-installed
insulated plenum.

6
Features/Benefits (cont)
42SG — Furred-in-stack 42SJ — Back-to-back
furred-in stack
42SH — Cabinet stack
The furred-in-stack is a single unit, con-
structed of 18-gage galvanized steel
designed for concealed applications in
corners or along room walls. After instal-
lation of the unit, only the supply-air
grille, room thermostat, and decorative
return-air grille access panel are visible.
The return-air grille is removable to allow
access for servicing major components.
The grille is furnished in a arctic white-
colored enamel-baked finish. Other col-
ors are available.
The 42SG is also available in master/
slave unit pairs. The pairs are actually 2
separate units shipped individually and
installed and piped together in the field.
The master unit includes risers with
stubout for field piping connections to the
slave unit which has no risers of its own.
The back-to-back furred-in stack is
designed for installation in the separation
wall between 2 separate rooms. The unit
is constructed of 18-gage galvanized
steel. The unit consists of 2 separate
units piped to a set of common risers.
Each unit has its own valves and con-
trols. After installation of the unit, only
the supply-air grille, room thermostat,
and decorative return-air grille panel are
visible.
The return-air grille is removable to allow
access for servicing major components.
The grille is furnished in a arctic white-
colored enamel-baked finish. Other col-
ors are available.
The cabinet stack unit is designed for
applications where concealed installa-
tions are not possible or practical. The
unit is constructed of 18-gage galva-
nized steel with a Arctic White-colored
enamel-baked finish. This model fea-
tures a double-deflection supply-air grille
and an integral return-air grille access
panel. Controls are normally mounted on
the unit but may also be remote wall
mounted.

7
Factory-installed options
Coils — Choice of a 2-pipe or 4-pipe system with the fol-
lowing chilled/hot water coil configurations:
• 2-Row Coil (42VC, VE, VG only)
• 3-Row Coil - 42C, D, V, S
• 4-Row Coil - 42D, S
• 4-Row High Capacity - 42V, C, S
• 3-Row High Capacity - 42VC, VE
• 3/1 Opposite End Coil Connections - 42C series,
42VA, 42VB, 42VF
• 3/1 Same End Coil Connections - 42C series, 42VA,
42VB, 42VF, 42S
• 2/1 Same End Coil Connection - 42VC, VE
• 3/2 Opposite End Coil Connections - 42C series,
42VA, 42VB, 42VF, 42S
• 3/2 Same End Coil Connection - 42C series, 42VA,
42VB, 42VF
• 4/1 Opposite End Connections - 42D
• 4/1 Same End Connections - 42D, 42S
• 4/1 High Capacity Opposite End Coil - 42C series,
42VA, 42VB, 42VF
• 4/1 High Capacity Same End Coil - 42C series, 42VA,
42VB, 42VF
• 4/2 Same End Coil Connections - 42D
• 4/2 Opposite End Connections - 42D
• 6-Row High Capacity Coil - 42D
• 6/1 Opposite End Connection - 42DA, DC, DE, DF
• 6/1 Same End Connection - 42DA, DC, DE, DF
• 6/2 Opposite End Connections - 42DA, DC, DE, DF
• 6/2 Same End Connection - 42DA, DC, DE, DF
Decorator colors — A wide variety of colors (Cham-
pagne Beige, Toffee Brown, Ermine Grey, and Polar
White) are available to match any interior décor. Select a
desired color from a paint chip chart, Catalog number
842-011, or provide paint chip for matching. Standard
color is now Arctic White; the other colors require a special
quote. Decorative colors may be applied to:
• Cabinet of 42VB, VF, VE, VG
• Cabinet of 42CG
• Panels 42S
• Bottom Panels of 42CK
• Wall Panels of 42VA
• Cabinet 42DF
Electric heaters — Coils are of high grade single-phase,
nichrome resistance wire, insulated by ceramic insulators in
plated steel brackets. Heater sizes available are shown in
the application data section for the respective units. Not
available on 42VG units.
Filters — Each unit (except the 42CA, VG unit) includes a
fiberglass throwaway filter sized for low velocity and maxi-
mum efficiency. The standard option will filter both return-
and outside-air. Optional permanent aluminum filters with
cleanable, non-aluminum filter media are available for
42CE, CF, CG, CK, DC, DD, DE, all 42V series, and all
42S series units.
Manual air vents — Each standard coil includes a man-
ual air vent to allow venting at the coil if necessary for
quick, complete air elimination.
Outside-air opening/damper — Damper is adjustable
from 0 to 25% and provides ventilation air to unit. (Avail-
able on 42VA, VB, VF and 42S series units.)
Single power source connection — Provides factory-
installed junction box to allow use of single power source
for motor and heater when they are of the same voltage.
For 42D and 42S series units.
Stamped toe space return-air grille — (42VB,VF units.)
Tamperproof “Camloc” fasteners — Camloc fasten-
ers are installed on the access panels and are available for
all cabinet model units.
Thermostat control packages — The standard ther-
mostat control option is line voltage. Unit-Mounted line
voltage and 24V thermostats are available on the 42V
series units. For thermostat control package options refer
to pages 10-12.
Field-installed accessories
Automatic air vents — Automatic air vents have fiber
washers which allow air in the pipes to pass through, auto-
matically bleeding the system, and eliminating the need to
manually remove air from the system. When wet, washers
swell and seal the system.
Decorative wall panels — Wall panels are available for
use with fully recessed 42VA units.
Drip lips (removable drain extension) — Drip lips are
frequently used when valves are added after unit installa-
tion and space limitations will not permit use of an
extended drain pan. The drip lip is placed on the end of
the drain pan and is pitched toward the pan to ensure
proper drainage. The drip lip gives positive control of con-
densate from valves and controls on 42DA, DC units (avail-
able as an option on 42DE, DF units). Provided as standard
on these units when factory-supplied motorized valve pack-
age is ordered. The drip lip is also installed on the 42C
series ceiling fan coil units when 2-way or 3-way motorized
valve packages are ordered.
Panels, frames, and grilles — Panels, frames, and
grilles on the 42S series units can be chosen in a wide vari-
ety of combinations to suit room decorating requirements
and allow access to the unit for maintenance. Discharge
grilles are double deflection type, aluminum finish or
painted. Return-air access panels containing return-air
grilles are available in five different types as illustrated on
page 97.
PANELS, FRAMES AND GRILLES
PANEL
NO. DESCRIPTION
1
Standard, 18-gage galvanized steel. Coated with baked-on
Arctic White enamel finish. Attached to unit with
1
/
4
turn
fasteners.
2
18-gage galvanized steel. Coated with baked-on Arctic White
enamel finish. Includes access door for concealed unit-
mounted controls.
3
Bar-type extruded aluminum with frame matching double
deflection supply grille. Fastens to wall and unit with 1
1
/
2
in.
long screws.
4
and
5
18-gage galvanized steel. Coated with baked-on Arctic White
enamel finish. Frame mounted on sheetrock with screws.
Panel mounted in frame with
1
/
4
turn fasteners.
All Each panel provides access to all internal components.
Options and accessories

8
Return-air grilles — Stamped-type return-air grilles are
standard on 42C, V, S units. Anodized aluminum hinged
bar-type grilles are installed on 42CG, CK and DF (avail-
able as an option on 42DA, DC, DE, DD) units.
Risers — The 42S series units can accommodate ¾-in.
(supply and return) and 1-in. (drain) to 2½-in. riser sizes in
2-pipe systems. For other applications, such as reverse
return risers or 4-pipe systems, it may be necessary to
accommodate the additional risers.
Condensate drains are available in sizes down to 1-in. for
greater cost economy. Riser size-reducers are factory-
installed and for risers of over 115-in. length, filler pieces
can be furnished for field installation.
Riser expansion — When necessary, the 42S series
units are provided with factory-installed expansion loops.
These expansion loops provide up to 1 ½-in. of riser
expansion within the standard unit construction. This
means that the unit can be used on installations of up to 20
floors without any additional expansion devices.
Risers material and insulation — The 42S series unit
factory-installed supply, return, and drain risers can be fur-
nished in type M or L copper. All factory-furnished risers
are insulated with flexible closed foam insulation in ½-in. or
¾-in. thickness.
Supply-air grilles — Two types of double deflection
supply-air grilles are available for horizontal and vertical
units; an integral steel grille painted to match the unit or a
separate unpainted anodized aluminum grille. Not applica-
ble to 42VG units.
Tell-tale drain pan — A secondary drain connection is
located above the primary drain to act as a “tell-tale” in the
event that the primary drain becomes obstructed. They can
be applied to either the main drain pan or an extended
main drain pan. This option only available on the 42C,
42V (except 42VG), and 42DA, DC, DE, DF.
Thermostats control packages — The standard ther-
mostat control option is line voltage. Wall-mounted line
voltage and 24-v thermostats are available on the 42 series
fan coil units. 24-v thermostat is not available on the
42VC,VE,VG unit. Thermostat control packages options
refer to page 10-12.
Trim strips — Strips are available for use with partially
recessed vertical 42VA units and 42S only.
Wall boxes — Wall boxes are all aluminum with insect
screen behind louvers. The wall boxes are available on all
42V series units except the 42VG units.
Options and accessories (cont)
DRIP LIP
(Horizontal Unit)
“TELL-TALE” DRAIN PAN
(Horizontal Unit)

9
AVAILABLE OPTIONS AND ACCESSORIES
LEGEND
AVAILABLE
FACTORY-INSTALLED OPTIONS AND
FIELD-INSTALLED ACCESSORIES
UNIT SERIES — 42
Ceiling — Horizontal Floor — Vertical Ducted — Horizontal Stack — Vertical
CA CE CG CK CF VA VB VF VC VE VG DA DC DE DF DD SG SH SJ
AIR VENT
Automatic Air Vent •••••••••••••••• • • •
Manual Air Vent Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std
CABINET CHANGES
Front Panel, 16 Gage ••
Front Panel, 18 Gage Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std
Extended Cabinet when Electric Heat
or Valves are Installed ••
Valve Compartment Extension, 10 in. •
Stamped Toe Space Return Grille ••
COILS
2-Row (Cooling Only) Std Std Std
3-Row (2-Row Cooling, 1-Row Heating) ••
3-Row (High-Capacity) Std Std Std Std Std Std Std Std • • • • • • • Std Std Std
4-Row (3-Row Cooling, 1-Row Heating) • ••••••• ••••• • • •
4-Row (High-Capacity) • ••••••• StdStdStdStdStd• • •
5-Row (4-Row Cooling, 1-Row Heating) •••••••• ••••• • • •
5-Row (3-Row Cooling, 2-Row Heating) •••••••• •••••
6-Row (4-Row Cooling, 2-Row Heating) •••••
6-Row (High-Capacity) •••••
7-Row (6-Row Cooling, 1-Row Heating) •••••
8-Row (6-Row Cooling, 2-Row Heating) •••••
DAMPERS
Manual — Adjustable through Return
Air Opening ••• • • •
Manual Adjustment, Remote Mounted ••• • • •
Manual — Rear Opening with ••• • • •
Sliding Damper — Not Filtered •••
Outdoor Air Connection (6 in.), with
Filter and with or without Damper •••
Damper, Linkage and Motor Wired to
Auxiliary Contact of 3-Speed Switch •••
DECORATIVE COLORS
(See Carrier Fan Coil Paint Selector
Guide) •• ••• •• • • • •
DISCHARGE GRILLES
Stamped Front Discharge Std Std Std Std Std
Double Deflection, Installed ••••
Double Deflection, Shipped Loose • • • • Std Std Std Std Std Std Std Std
DRAIN PANS
Sprayed on Closed-Cell Foam on Inside
Main Drain Pan Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std
Auxiliary Plastic Drain Pan Std Std Std
Auxiliary Steel Drain Pan Std Std
AuxiliaryDripLip—Includedwith2-or
3-Way Motorized Valves ••••• StdStd••
Tell-Tale, with Second Drain Connection •••••••••• ••••
Stainless Steel •••••••••••••••• • • •
DUCT COLLAR
Discharge Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std
ELECTRIC HEATERS
Nichrome Wire Strip Heater ••••• ••••• • • •
Sheath Type Heater •••••
FAN SWITCH
Unit-Mounted, Wired and Installed Std Std Std Std Std Std
Wall-Mounted with Plate for
Field-Mounting Std Std Std Std Std Std Std Std Std Std Std Std Std
FILTERS
Permanent Filter ••••••••• •• • • • •
Throwaway Filter Std Std Std Std Std Std Std Std Std
LEVELING LEGS • • • • • Std Std Std Std Std Std Std
INSULATION
Foil Faced Insulation •••••••••••••••• • • •
Tuf -Ski n II Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std
Tuf-Skin RX Insulation •••••••••••••••• • • •
MOTORS
120-1-60, 3-Speed Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std
208-1-60, 3-Speed •••••••••• ••••• • • •
230-1-60, 3-Speed •••••••••• ••••• • • •
277-1-60, 3-Speed •••••••••• ••••• • • •
220-1-50, 3-Speed •••••••••• ••••• • • •
MOTOR QUICK-DISCONNECT PLUG Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std Std
OUTSIDE-AIR WALL BOX •••
RETURN AIR GRILLE, Shipped Loose
Stamped Return Grille Std Std Std Std Std Std Std Std Std Std Std Std Std Std
Hinged Panel Std Std • • • Std •
TAMPERPROOF LOCKS (Camloc)
Access Panels ••• •• • • •
Access Doors ••• ••
VALVE PACKAGES •••••••••••••••• • • •
WALL PANELS (for Recessed Unit) •
WIRING PACKAGES •••••••••••••••• • • •
•—Available as a Factory-Installed Option or a Field-Installed Accessory
Std — Standard

10
Use the Control Selection guide to make sure that all
necessary components are provided for and that the com-
ponents are compatible with the required control system.
NOTE: When thermostatic fan control is selected or when
unit outside air dampers are used, unit-mounted thermo-
stats are not recommended as their use will result in poor
room temperature sensing.
CONTROL SELECTION GUIDE
*If system is HEATING-ONLY or COOLING-ONLY, no changeover or bypass is required.
NOTE: Unit-mounted thermostats are not recommended with either fan-cycle control or applications with outside air dampers.
SYSTEM DESCRIPTION THERMOSTAT
CHANGEOVER
ON
SUPPLY PIPE
VALVE FAN
SWITCH (SW) NOTES
2-PIPE HEATING-COOLING*
Fan
Control
(2-Pipe)
Fan manually cycled None None None Standard 3-Speed
SW
Not recommended
for high humidity
application
Thermostat cycles fan on-off
from speed set with fan switch.
Wall mounted includes
heat-cool switch.
None None Thermostat has inte-
gral 3-Speed SW
Thermostat cycles fan on-off
from fan speed set with switch.
Mode automatically switched
by changeover sensing water
temp.
Wall mounted.
Heating/cooling
Thermostat
Yes None Standard
3-Speed SW
Unit-mounted thermostats
provide very poor room
temperature control
Thermostat cycles fan from
high to low on cooling and low
to off on heating.
Wall or unit mounted Yes None No Standard 3-Speed
Switch, ON-OFF tog-
gle SW only
Best fan cycle control for
high humidity applications
Two-
position
electric
valves
(2-pipe)
Thermostat cycles valve
open or closed.
Wall mounted includes
heat-cool switch.
None Motorized (N.C.)
3-way or 2-way,
no bypass required.
Thermostat has inte-
gral 3-Speed SW
Valve packages with belled
end(s) for field soldering to
coil.
Thermostat cycles valve
open or closed. Mode auto-
matically switched by
changeover sensing water
temp.
Wall or unit mounted.
Heating/cooling
Thermostat
Yes Motorized (N.C.)
3-way or 2-way
Standard 3-Speed
SW. Others have ther-
mostats with integral
3-Speed SW
ELECTRIC HEAT
Two-
position
electric
valve with
Auxiliary
Electric
Heat
(2-pipe)
Thermostat cycles valve
open or closed. 2° F after
valve closes, thermostat
activates electric heater.
Heater cannot turn on if hot
water is in coil.
Wall or unit mounted.
Sequenced heating
and cooling.
Ye s .
Two Required.
Motorized 3-way or
2-way
Standard 3-Speed
SW. Others have ther-
mostats with integral
3-Speed SW
Valve packages with belled
end(s) for field soldering to
coil.
Thermostat cycles valve
open or closed. Manual
changeover switch changes
thermostat to heat to activate
electric heater.
Wall mounted
includes heat-cool
switch.
None Motorized 3-way or
2-way, no bypass
required
Thermostat has inte-
gral 3-Speed SW
Valve packages with belled
end(s) for field soldering
to coil.
Two-
position
electric
valve with
total
electric
heat
(2-pipe)
Thermostat cycles valve
open or closed. Manual
changeover switch changes
thermostat to heat to activate
electric heater.
Wall mounted includes
heat-cool switch.
None Motorized (N.C.)
3-way or 2-way,
no bypass required
Thermostat has inte-
gral 3-Speed SW
Valve packages with belled
end(s) for field soldering
to coil.
Thermostat cycles valve
open or closed. 2° F after
valve closes, thermostat acti-
vateselectricheater.
Wall or unit mounted.
Sequenced heating
and cooling
None Motorized (N.C.)
3-way or 2-way,
no bypass required
Standard 3-Speed
SW
4-PIPE
Two-
position
electric
valves
(4-pipe)
Thermostat cycles cooling and
heating valves open or closed.
Wall mounted includes
subbase with heat-
cool switch.
None Motorized (N.C.)
3-way or 2-way
(requires 2 valves)
Thermostat has inte-
gral 3-Speed SW
Valve packages with belled
end(s) for field soldering
to coil.
Thermostat cycles cooling
valve open or closed. 2° F
after valve closes, thermostat
cycles heating valve open or
closed.
Wall or unit mounted.
Sequenced heating
and cooling.
None Motorized (N.C.)
3-way or 2-way
(requires 2 valves)
Standard 3-Speed
SW. Others have
thermostats with inte-
gral 3-Speed SW
Controls

11
Remote-mounted controls
Standard 3-speed switch — This standard switch has 4
positions: OFF, HIGH, MEDIUM, and LOW. Switch has
auxiliary contact that is energized when switch is in HIGH,
MEDIUM or LOW position.
Some of the options common with the 3-speed switch are:
1. Unit-mounted switch on Furred-In Vertical Model.
(Available as special order on Horizontal Models)
2. Switch without OFF position.
3. Key-operated switch.
Standard remote-mounted thermostat or
optional unit-mounted thermostat
24-V Debonair® thermostat — Features large Ther-
moglow™ display, Neverlost™ memory, Exact Fit™ locking
cover, Smart Fan™ dynamic fan speed control, 4-pipe,
2-pipe automatic changeover applications with adjustable
dead band. Programmable and non-programmable models
available.
Optional remote-mounted thermostat
Line voltage T155 thermostat — Features 50 to 90 F
temperature range, manual 3-speed fan control, mount is a
standard 2 x 4 in. box, 4-pipe, 2-pipe and autochangeover
applications. Available in vertical or horizontal styles.
Unit-mounted controls
Standard 3-speed switch — Switch has OFF, HIGH,
MED and LOW positions. Switch is also equipped with
auxiliary connection energized when switch is in HIGH,
MED or LOW position.
Combination thermostat/3-speed switch — Includes
thermostat for 2-pipe or 4-pipe system and standard
3-speed switch. Thermostat and 3-speed switch are unit-
mounted in a common electrical junction box. The special
combination allows for the fan coil unit to have control for
the valve cycle only.
COOL
HEAT
AUTO
R
OFF
HI
MED
LO
OFF
HI
MED
LO

12
Four-pipe thermostat, model TH104 — With this
thermostat, heating and cooling are sequenced (automatic
changeover) with 6 degree separation between HEATING
ON and COOLING ON. The standard temperature range
is 60 to 90 F.
Two-pipe thermostat, model TF103 — Single-pole
double-throw (SPDT) thermostat has snap action contacts.
The standard temperature range is 60 to 90 F.
Automatic changeover (Summer-Winter switch) —
The automatic-changeover thermostat is a single-pole
double-throw (SPDT) thermal switch in a moistureproof
and dust-proof enclosure. Thermostat mechanism and lead
ends are hermetically sealed in a polypropylene enclosure
with epoxy resin. Device clamps on coil supply pipe with
end snap-on clip.
The set point temperatures are factory set. When water
temperature rises above 80 F (approximately), the thermo-
stat switches to the winter cycle. When water temperature
drops below approximately 70 F, the thermostat switches
to the summer cycle. Switch reset is automatic.
Fan coil control relay board — The fan coil relay board
is used in conjunction with the Debonair thermostat or a
CCN fan coil controller to regulate a single-speed or multi-
speed fan. The fan coil relay board can also be used to con-
nect the fan coil controller to a line voltage valve actuator.
The fan coil relay board is factory shipped as a PC board
with four
1
/
2
-in. stand-offs attached for field mounting.
NOTE: One fan coil relay board is used for each applica-
tion. Fan coils with two or more fan motors use a fan coil
relay board for each fan motor. A maximum of three fan
coil relay boards can be wired to one fan coil control.
Controls (cont)
STEMCO
416-79
L80 8220
AUTOMATIC CHANGEOVER
(Summer-Winter) SWITCH
G
G2/(W)
G3/(Y)
COM
FAN
(VALVE)
(COOL)
HI
(HEAT)
MED
LO

13
Basic definitions
Unit hand — When facing the supply air outlet from the
front of the unit (air blowing in your face), your right hand
will be the right hand side of the unit and your left hand the
left hand side of the unit.
Same end connection (2 pipe or 4 pipe) — All piping
connections are on the same end (side) of the unit. Con-
trols and electrical connection will be on the end (side)
opposite the piping connection.
Standard 2-pipe units will be the same end connection.
Opposite end connection (4-pipe option) — Hot
water (HW) piping connections and electrical will be on the
end (side) opposite the chilled water (CW) and drain
connections.
Application data
UNIT HAND
SAME END CONNECTION
NOTE: Piping determines the hand of the unit.
OPPOSITE END CONNECTION
NOTE: Chilled water piping determines the hand of the unit.

14
System piping
The following diagrams show some common methods
used to pipe the 42S series units. Only the 2-pipe systems
are shown; however, the methods would be the same for
4-pipe systems.
System 1, the “direct return” system, is the most common.
It is economical to install since it supplies and returns the
water for a riser column from the same location, at the top
or the bottom of a building. This type of riser arrangement
does require more attention to individual unit water flow
balancing. The risers are normally capped at the end as
shown in the diagrams.
System 2, the “reverse return” system, is used to minimize
the requirement for individual unit balancing. This system
is usually referred to as the self-balancing system. The
arrangement of the risers allows the water flow for each
unit in a column to be equalized. In the reverse return sys-
tem both the supply and return mains are located at the
top or the bottom of a building requiring an additional
return riser to be furnished in the units.
System 3, the “common reverse return” system, typically
has the supply and return mains located remotely from
each other — such as one at the top and one at the bottom
of a building. This eliminates the need for a reverse return
riser in the units.
Application data (cont)
SYSTEM 1 — DIRECT RETURN
SYSTEM 2 — REVERSE RETURN
SYSTEM 3 — COMMON REVERSE RETURN

15
Risers
Riser diameter is an important consideration in the design
of stack series systems. Standard units can accommodate
3
/
4
-in. to 2
1
/
2
-in. riser sizes in 2-pipe systems. For other
applications, such as reverse return risers or 4-pipe sys-
tems, it may be necessary to accommodate the additional
risers.
Riser size is based on the water flow needed for a given
tier of units. Unit risers are sized according to the diameter
and length requirements as specified by the customer. To
determine riser size, water velocity should be limited to 5 to
8 ft/second. Thus, if 10 units are to be stacked vertically
with each unit requiring 3 gpm, the maximum flow in the
risers is 30 gpm. Through 1
1
/
4
in. risers, this is a velocity
of 7.5 ft/second. The maximum flow rate of 30 gpm
occurs only at the supply and return points. As the water
moves upward, the flow in the supply riser is reduced by
3 gpm per floor, so that after 3 floors, the total flow is
21 gpm and riser size can be reduced to one inch. See
chart on page 103.
Condensate drains are available in sizes down to one
inch for greater first cost economy.
Riser size-reducers are factory installed and caps are pro-
vided at customer request.
For risers of over 115 in. length, filler pieces can be fur-
nished for field installation.
Typical arrangements
Typical arrangement applications for each model type are
shown below. The fan coil units feature almost an unlim-
ited number of arrangements to meet the needs of new
construction, renovation, or reconstruction. Consult the
factory for the arrangement (standard or special) to meet
your particular need.
42SH — EXPOSED CABINET
42SG — FURRED-IN STACK 42SG — FURRED-IN STACK MASTER/SLAVE UNIT
42SJ — BACK-TO-BACK FURRED-IN STACK

16
PIPING COMPONENTS
LEGEND
*Check all system component pressure ratings (coils, values, pumps,
etc.) with manufacturer and any applicable local or national piping
codes prior to specifying system pressure rating.
SYMBOL/SKETCH DESCRIPTION C
V
FACTOR RATING* STEAM
USE
1
/
23
/
4
PSI F
MANUAL AIR VENT: Threaded brass needle
valve with screwdriver slot for adjustment.
Application — Body brazed into high point of
heating and cooling coils for bleeding air from
coil. Standard item on all hydronic coils (not
used on steam or DX coils). Should not be
used in lieu of main system air vents.
N/A N/A 400 100 NO
AUTOMATIC AIR VENT: Nickel plated brass
valve, fiber-disc type, with positive shut-off
ballcheck and quick vent feature via knurled
vent screw.
Application — Optional replacement for man-
ual air vent. Automatically passes minute
quantities of air through the fiber discs which
expand upon contact with water, completely
sealing the valve. As air accumulates, the fiber
discs dry and shrink, repeating the cycle. Not
recommended for removing large quantities of
air encountered during initial start-up or subse-
quent draining and refilling. Should not be
used in lieu of main system air vents.
N/A N/A 125 240 NO
SWAGE: Copper tube end expanded to accept
a copper tube of the same size for factory or
field brazing.
Application — Used where possible for all tub-
ing joints for best joint integrity.
N/A N/A 300 200 YES
UNION: Combination wrought copper/cast
brass union assembly, solder by solder.
Application — Used for quick connect (and dis-
connect) of valve package components to min-
imize field labor and facilitate servicing of unit.
N/A N/A 300 200 YES
INSERTION TEST PORT: Brass body valve
for acceptance of test probe (up to
1
/
8
in.
diameter).
Application — Installed on one (or both) sides
of the coil to allow for temperature or pressure
sensing. Used for close tolerance water bal-
ancing and service analysis.
N/A N/A 250 250 NO
Cv — Coefficient of Velocity
DX— Direct Expansion
Application data (cont)

17
PIPING COMPONENTS (cont)
LEGEND
SYMBOL/SKETCH DESCRIPTION C
V
FACTOR RATING STEAM
USE
1
/
23
/
4
PSI F
PRESSURE TEST PORT: Brass body
1
/
4
ser-
vice access fitting with removable depressor
type core.
Application — Installed on both sides of the
coil to allow for pressure sensing. Attach
pressure gages to facilitate close tolerance
water balancing.
N/A N/A 400 210 NO
GAGE COCK: Brass shut-off valve with
1
/
4
FPT fitting for attachment of pressure
gages.
Application — Installed on both sides of the
coil to allow for pressure sensing. Attach
pressure gages to facilitate close tolerance
water balancing. May be used in bleed
bypass line to regulate water flow.
N/A N/A 200 250 N/A
CIRCUIT SETTER: Variable water flow bal-
ancing valve with manual adjustment knob,
pointer, percent-open scale, memory stop
and integral pressure read-out ports.
Application — Used for close tolerance water
flow balancing. Positive shut-off ball valve
feature allows usage as combination balanc-
ing and shut-off valve.
2.12 3.9 300 250 NO
BALANCE VALVE: Variable water flow man-
ual balancing valve with screwdriver slot
adjustment screw.
Application — Often used in conjunction with
test port fittings for water flow balancing. Bal-
ance by temperature differential or coil pres-
sure drop (check specifications for service
fittings required if balancing by pressure
drop). May be used in 3-way valve bypass
line to permit equal flow balancing.
3.0 8.9 150 200 NO
FIXED FLOW VALVE: Flexible orifice type
(non-adjustable).
Application — Used for water flow balancing.
Valve automatically adjusts the flow to within
10% of set point. Requires 15 psi
(35 ft) of additional pump head for proper
operation.
Valve orifice size
determines C
V
fac-
tor. The orifice of
these fixed flow
valves changes as
flow is regulated.
As the water pres-
sure increases,
the orifice size
decreases,
thereby automati-
cally limiting the
flow rate to the
specified gpm
(±10%).
150 160 NO
Cv — Coefficient of Velocity
DX— Direct Expansion
FLOW

18
PIPING COMPONENTS (cont)
LEGEND
SYMBOL/SKETCH DESCRIPTION C
V
FACTOR RATING STEAM
USE
1
/
23
/
4
PSI F
STRAINER: Y-type body with 50 mesh stain-
less steel screen.
Application — Used for removal of small parti-
cles from system water during normal system
operation. Should not be used in lieu of main
system strainers. Strainer screen may have to
be removed during initial high pressure sys-
tem flushing during start-up. Screen should be
removed and cleaned per normal mainte-
nance schedule (provisions for strainer blow-
down not provided).
9.0
Clean
19.0
Clean 400 250 N/A
GATE VALVE: Manual shut-off valve.
Application — Used for unit isolation during
system flushing, servicing, etc. Do not use for
water balancing.
19.8 36.0 200 200 NO
GLOBE VALVE: Standard pattern, manual
shut-off and throttling valve.
Application — Used for unit isolation. Not rec-
ommended for high flow rates due to relatively
high pressure drop.
1.8 3.9 200 200 NO
COMPRESSION STOP VALVE:
Manual shut-off valve.
Application — Used for unit isolation during
system flushing, servicing, etc. Not recom-
mended for high flow rates due to relatively
high pressure drop.
2.3 5.4 150 200 NO
BALL VALVE: Manual balance and shut-off
valve.
Application — Used for unit isolation and
water flow balancing. Without memory stop
feature water balance point must be marked
by installer (if necessary). Check specifica-
tions for service fittings required when used
for water balancing.
4.0 7.5 400 200 YES
BALLVALVEWITHMEMORYSTOP:
Manual balance and shut-off valve.
Application — Used for unit isolation and
water flow balancing. The adjustable memory
stop feature allows return to the balance point
after shut-off. Check specifications for
service fittings required when used for water
balancing.
4.0 7.5 400 200 N/A
Cv — Coefficient of Velocity
DX— Direct Expansion
Application data (cont)

19
PIPING COMPONENTS (cont)
LEGEND
NOTES:
1. Motorized 2-way valves have a maximum close-off differential of 25 psi.
2. Motorized 3-way valves have a maximum close-off differential of 10 psi.
SYMBOL/SKETCH DESCRIPTION C
V
FACTOR RATING STEAM
USE
1
/
23
/
4
PSI F
2-WAY MOTORIZED VALVE: Electric 2-posi-
tion flow control valve (open/closed). Normally
closed body with manual override lever.
Installedinsupplylinetounit.
Application — All standard control and valve
packages are based upon normally closed
valves (valve electrically powered open and
closed by spring return when electric power
removed). Manual override lever allows valve
to be placed in the open position for second-
ary (unit) flushing, constant water flow prior to
start-up, etc. Manual override is automatically
disengaged when valve is electrically acti-
vated. Consult factory for normally open
valve applications.
2.3 2.3 300 200
YES
15
PSI
MAX.
3-WAY MOTORIZED VALVE: Electric
2-position flow control valve (closed to coil/
open to bypass or open to coil/closed to
bypass). Normally closed with manual over-
ride lever. Installed in supply line to unit.
Application — Same comments as 2-way
motorized valve except with manual override
lever engaged the valve is open to both ports
and water flow will take the path of least resis-
tance through the valve package (not neces-
sarily 100% through the coil).
5.0 5.0
300 200 N/A
SERVICE
2.8 2.8
BYPASS
MODULATING VALVE
(Non-Spring Return): Modulating valves are
designed to control the flow in the circuit by
making incremental adjustments to the flow
path within the valve.
Application — To control fluid flow in fan coil
units.
4.0 300 200 N/A
MODULATING VALVE
(Spring Return): Modulating valves are
designed to control the flow in the circuit by
making incremental adjustments to the flow
path within the valve.
Application — Same comments as non-spring
return except when powered, the actuator
moves to the desired position, at the same
time tensing the spring return system. When
power is removed for more than two minutes
the spring returns the actuator to the normal
position.
4.0 300 200 N/A
AQUASTAT: Water temperature sensing elec-
trical switch.
Application — Clips directly on nominal
size
1
/
2
in. or
3
/
4
in. copper tubing for water
temperature sensing. Must be correctly
located for proper control operation.
Cv — Coefficient of Velocity
DX— Direct Expansion

20
Valve packages
There are limitations on physical size of pneumatic valves,
quantity and type of matching components, and required
control interface. See Symbols and Placement of Valves
diagram.
Consult factory before ordering any special valve pack-
age components that are not covered in this book.
Valve packages are shipped with the units or in unit car-
tons. Valve packages include belled ends for field soldering
to coil connections.
All factory-furnished cooling valve packages are
arranged to position as much of the package as possible
over an auxiliary drain pan or drip lip. This helps minimize
field piping insulation requirements.
Application data (cont)
SYMBOLS AND PLACEMENT OF VALVES
Coil Connections (Positions A & B) — When isolation valve only is added to supply or return line, the isolation valve will be factory
brazed to the coil stub-out. Addition of any other component or connection to the supply or return line will change the respective coil
connection(s).
Service Fittings (Positions C & D) — Optional fittings for attaching pressure/temperature sensing devices to obtain pressure drop or tem-
perature differential across coil. Used with ball valve or balance valve where extremely accurate water flow balancing is required.
Water Flow Balancing (Positions E, F, & H) — Only one device per total valve package to be used for balancing water flow through the
coil. When isolation valve (ball valve or ball valve with memory stop at position H) is used for water flow balancing, do not specify additional
balancing device at position Eor F. When balancing device is specified at position Eor F, isolation valve does not require balancing feature
at position H(with a 3-way motorized valve, a bypass balancing valve may be specified in the bypass line to permit equal flow balancing).
Strainer (Position G) — Does not include blow down fitting and should not be used in lieu of main piping strainers.
Isolation Valves (Positions H & J) — Normally requires one each on supply and return line (see exception under circuit setter). When
position His used for balancing (ball valve or ball valve with memory stop), check specifications for service valve requirements.