Heat Controller Small Duct, High Velocity Quick Start Manual

INSTALLATION

INSTRUCTIONS

SMALL DUCT HIGH VELOCITY:

Duct Layout

Heat Controller, Inc. • 1900 Wellworth Ave. • Jackson, MI 49203 • [phone] • www.heatcontroller.com

Bulletin 100-135 / August 2010

Installation Guide

This instruction is a summary of the basic rules and applies to most applications.

Duct Layout

Outlets

 7 two inch outlets Per Ton / 5 two and a half inch outlets Per Ton (3.5 kW). For refrigerant cooling applications the

airflow must be between 200 and 250 CFM per nominal ton [27 to 33 L/s per nominal cooling kW]. For hot water or chilled
water systems, refer to performance charts for determine the required airflow. The allowable airflow range per 2 inch outlet
is 20 to 40 CFM [9.4 and 19 L/s] and 25 to 55 CFM [11.8 and 23.75 L/s], where the typical ou tlet will deliv er 35 CFM [17
L/s] if the plenum static pressure is 1.5 inches [0.37 kPa] and the branch duct length is 10-foot (3 meter) without any
balancing orifices. Therefore, the average project will require about 7 2 inch outlets or 5 two and a half inch outlets per
nominal ton although more will be needed if the branch ducts are longer, balancing orifices are used, the plenum static
pressure is less than 1.5 inches of water [0.37 kPa], or it is desirable to make the system as quiet as possible. For example,
two runs with 50% balancing orifices are equal to one branch run without any orifices.

 10% Rule. For supply ducts longer than 10 feet (3 meter), the air is reduced in that run by 10% for every 5 feet over 10

(every 1.5 meter over 3 meters). For example, a 30 foot [9 meter] run is 60% of an outlet that is 10 foot [3 m] yielding a



reduction of 40% (30-10=20, 20

 Consider Traffic Pattern. Place outlets out of traffic pattern. A corner, 5-inch [127 mm] from each wall, is a good location,

or along walls, or in soffits blowing horizontally. Consider floor outlets (with screens) for units located in basement. Slotted
outlets can be used for high wall locations or in ceilings where there is insufficient room for bending tubing.

 Allow for Aspiration. Locate outlets so the air stream does not impinge on any objects or people — at least 3 feet [1 m]

away. Use outlet deflectors and outlet balancing orifices sparingly as they disrupt the aspiration.

 Minimize Length, Minimize Restriction. Keep the supply duct length as close to 10 feet [3 m] as possible and never less

than 6 feet [1.8 meters]. Use the fewest number of bends as possible. Maximize the radius of any bends making sure the
bend in the sound attenuator tubing near the outlet is at least 6-inch [152 mm].

Plenum

 Maximize Length, Minimize Restriction. Run main trunk (plenum) as long as possible; it is better to lengthen the plenum

if you can shorten even two outlet runs. Use full flow tees with turning vanes (when applicable) and full flow elbows. The
maximum total plenum length is 150 ft [45 m]; consider the first tee equal to 30 ft [9 m] and elbows equal to 15 ft [4.6 m].

 60/40 Rule. When using a tee split the flow as close to 50/50 as possible — no more than 60/40. Always use a turning vane.
 70/30 Rule. Turn the tee 90° to make a side branch with no more than 30 percent of the air. Do not use a turning vane
 Horseshoe Patterns. (Best Method). Use a tee at least 24 inches [610 mm] off unit. For the 4860 unit, use 10-inch [254

mm] metal up to and including tee; then use 9-inch [229 mm] both directions. For the 3642 unit, use 9-inch [229 mm]
insulated metal up to and including tee; then use 7-inch [178 mm] both directions. If possible, close the horseshoe into a
perimeter loop.

5=4, 410=40%).

PERIMETER LOOP SYSTEM

DOGLEG SYSTEM

Note — Specifications, Ratings, and Dimensions are subject to change without notice. Copyright© 2010 Heat Controller, Inc.

IL00121.CVS

IL00123.CVS

HORSESHOE SYSTEM

'H' SYSTEM

IL00122.CVS

IL00125.CVS

Bulletin 100-135 — Page 2

V

Plenum (cont.)

 Shotgun Pattern. For the SDAH48 and SDAH60 series units, use 10-inch [254 mm] insulated metal duct for the first 30

percent; then reduce to 9-inch [229 mm] if desired. For the SDAH36 unit, use 9-inch [229 mm] insulated metal duct for the
first 40 percent; then reduce to 7-inch [178 mm] if desired. For the SDAH24 unit, 7-inch [178 mm] may be run the entire
length.

40 %60 %

9-INCHDIA.

7-INCHDIA.

 24-inch (610 mm) Rule. Use at least 24-inch [610 mm] of straight plenum before any fitting, such as an elbow, tee, or

IL00124.CN

30% MAX.

IL00126.CNV

takeoff. Electric duct heaters require 48 inches [1.2 m]. Avoid elbows directly off units.

 Space Takeoffs Evenly. Maintain distance between takeoffs as evenly as possible. Space the takeoffs at least 6-inch [152

mm] apart and 12-inch [305 mm] from end cap.

Sound

 Sound Attenuators. Always use at least 3 feet [1 m] of the Heat Controller supplied sound attenuator supply tubing (SD-

26C or SD-226C) at the end of each run. For runs up to 12 feet [3658 mm], you may use the sound attenuator for the entire
run. For greater lengths, use the aluminum core supply tubing (SD-25 or SD-225) with a 3 foot [1 m] sound attenuator at the
end.

 Return Air Duct Attenuation. Use the Heat Controller Return Air Duct (SD-04) sheet metal with acoustical duct liner.

Never use flex duct with a solid plastic liner in place of SD-04.

 Isolation. Isolate the air handler with foam rubber strips under the unit. Either hang the unit from the structure using angle

iron framework under unit (do not hang directly with hooks in the cabinet) or set on a platform.

Piping

 Secondary Drain Pan. Always use a secondary drain pan wherever overflow of condensate can cause water damage. Do

not trap secondary drain line or connect to primary drainpipe. Place secondary drain line exit so that it is apparent when
being used. For example, pipe the drain line so it drips on an outdoor windowsill and causes splashing to be noticed.

 Primary Drain. Always trap primary drain line and run drain line per local plumbing codes.
 Refrigerant Lines. Follow outdoor section manufacturer's instructions for running refrigerant lines. Size and trap per their

instructions.

 Check Total System Airflow. Check the airflow at each outlet with a Turbometer centered over the outlet. Add up the cfm

for all outlets – it should not differ by +/- 5% from the design airflow.

STARTUP — DO THIS BEFORE BOXING-IN THE DUCT WORK.

 Check Static Pressure (optional). Measure the external static pressure in plenum 2 feet [610 mm] from unit and before any

fitting. Set as close as possible to 1.5 inches of water [0.37 kPa] or less, but no less than 1.0 IWC [0.25 kPa] or greater than

1.8 IWC [0.48 kPa], by providing a dequate number of full

 Check Amperage. Measure the amperage and voltage of the motor. Verify that it matches within +/- 5% of the values for

the desired (design) cfm in the installation manual or the motor amperage table shipped with each air handler. Also, use a
Turbometer

®

to measure airflow from each outlet. If the total airflow measured by the Turbometer at the outlets is

outlets and minimum plenum fittings (full flow).

significantly less than airflow determined by motor amperage, check for system air leaks.

 Check for Full Flow. Inspect each outlet for full flow (except where balancing orifices or used or for long branch ducts).

Investigate for blockage or kinks if flow is insu ffi ci ent.

 Check Refrigerant Charge. Charge unit per outdoor manufacturer's instructions and Unico's Installation instructions. For

best results use the subcooling method during the cooling cycle. Heat pu mps should be checked in both heating and cooling.

TurboMeter® is a registered trademark of Davis Instruments

INSTALLATION

INSTRUCTIONS

SMALL DUCT HIGH VELOCITY:

SDAH18 Air Handler

Heat Controller, Inc. • 1900 Wellworth Ave. • Jackson, MI 49203 • [phone] • www.heatcontroller.com

Bulletin 100-150 / August 2010

INSTALLATION MANUAL

SHAH18 Air Handler

NOTICE TO INSTALLER AND EQUIPMENT OWNER: RETAIN THIS MANUAL AT THE JOB

Il0015 9.CV5

General

The information on the following pages is to help the installer save
time, provide the best possible installation and insure continuous
trouble-free operation.

Scope

These instructions apply to the Heat Controller SDAH18 fan-coil
unit. Installation instructions for the air distribution system are
covered in other bulletins. Before beginning any installation, a
detailed system layout must be done in accordance with Bulletin
100-255 System Sizing and Layout bulletin.

SUFFICIENT BUILDING INSULATION IS
ESSENTIAL FOR THE MOST ECONOMICAL
OPERATION

General Precautions and Safety Tips

Do not attempt to install or startup unit without first reading and
understanding the appropriate sections in this manual. Before
operating, be sure the unit is properly grounded.

Installation should be in accordance with all local codes and
regulations and with the National Fire Protection Association and
Underwriters Laboratories applicable standards and regulations. In
case of conflict, local codes take precedence.

All electrical wiring should be in accordance with the latest edition
of the National Electrical Code and all local codes and regulations.

Condensate piping should be installed in accordance with
governing code.

Always install a secondary drain pan when an overflow of
condensate could cause damage.

TABLE OF CONTENTS

INTRODUCTION........................................................ 1

UNPACKING .............................................................. 2

LOCATION ................................................................. 2

SECONDARY DRAIN PAN ........................................ 3

MOUNTING................................................................ 4

Horizontal Platform .............................................. 4

Horizontal Suspended ......................................... 4

Ceiling.................................................................. 4

Vertical................................................................. 5

DUCT CONNECTION ................................................ 5

Supply Plenum..................................................... 5

Return Duct.......................................................... 5

PIPING ....................................................................... 6

Condensate Lines................................................ 6

Refrigerant Lines.................................................. 7

Expansion Valve ................................................... 7

Water Connections .............................................. 7

CHARGING AND STARTUP...................................... 8

Sequence of Operation........................................ 8

Fan Speed ............................................................ 8

Checking Airflow ................................................... 9

Charging a Cooling System .................................. 9

Low Ambient Control Kit ..................................... 11

Charging a Heat Pump System .......................... 11

Mild Weather Kit ................................................. 11

APPENDIX A - Hot Water Coil Capacities ................ 12

APPENDIX B – Chilled Water Coil Capacities .......... 12

APPENDIX C - Specifications ................................... 13

Part Numbers
This manual does not always include the latest revision
letter when referring to SD part numbers. Refer to the latest
Price List and Spec Sheets for the current revision letter.

INTRODUCTION

The Heat Controller Small Duct High Velocity air handler is
a complete indoor comfort system that includes an indoor
fan coil unit and small duct system. The fan coil unit and
duct system were designed to operate together to provide
the proper airflow in every installation. The conditioned air
is supplied through a series of two-inch or 2 ½ inch
diameter ducts as a stream of air that entrains and mixes
with the room air. This process of aspiration produces a
more even temperature distribution throughout the occupied
space.

Bulletin 100-150 — Page 2

Heating Only

Blower Cabinet

+ Hot Water Coil)

Cooling Only

Blower Cabinet

+ Cooling Coil

Horiz ontal
Flow

Vert ical
Up­Flow

Figure 1. Unit Arrangement

The Heat Controller SDAH18 fan-coil unit is a single
packaged unit. The cooling and heating coils are contained
within the same cabinet. The unit can be mounted in a
vertical up-flow or horizontal-flow configuration. The coils
can be combined as a heating-only, cooling-only, or heating
and cooling fan coil unit. See Fig. 1.

Heating and Cooling

Blower Cabinet
+ Hot water Coil
+ Cooling Coil

OUT

IN

IL00148.CV5

Open the carton to remove the unit. Inspect unit for visible
signs of concealed damage and notify carrier of any such
damage. All materials are sold FOB Factory and it is the
responsibility of the consignee to file any claims with the
delivering carrier for materials received in a damaged
condition.

The unit is available in one size; 38-in L x 20-in W x 12-in
H (965-mm x 508 mm x 305-mm). The heating only system
includes the blower/motor and a hot water coil. The cooling
only system includes the blower/motor and a cooling coil.
For the heating and cooling system both coils are provided.

The cooling coil may be a heat pump coil or a chilled water
coil. The electrical panel is located inside of the cabinet.

UNPACKING

All units are inspected prior to shipping and are carefully
packaged in individual cartons. Inspect all cartons prior to
unpacking. Notify carrier of any damage.

CARDBOA RD
SUP PORTS

Figure 2. Location of Motor Shipping Supports

Open the blow er access panel to remov e the
motor shipping support. See Fig. 2. . The
expansion valve is shipped loose and is located in
the coil compartment near the connections.

MOUNTING

The unit ships installation ready for either horizontal or
vertical airflow applications (see Fig. 1) and may be
mounted to a structure using the optional mounting rails
(SD- 95).

LOCATION

Locate the air handler to minimize the number of plenum
elbows and fittings while keeping the supply duct runs as
short as possible. (See Bulletin 100-250, Component
Layout). The fully insulated cabinet allows installation with
zero clearance to the top, bottom, or sides of the unit.
However, clearance must be provided for servicing which is
dependent on how the unit is installed. Servicing of the
blower/motor assembly and coils can be performed in three
different ways:

1. The complete top panel, which is attached to
blower/motor assembly, can be removed. To do this,
the motor leads must be disconnected in the control
compartment.

1 (25) Minimum

Supply plenum

1(25)Minimum

Supply Plenum

Supply plenum

All dimensions in inches (mm).

Side View

Air Flow

Air Flow

Air Flow

18 (457) bottom

clearance for

Top View

24(610) side

clearance for service

Suspended Installation

Side View

service

12

Return Duct

"
38
"

Return Duct

20
"

38
"

12

Return Duct

"

38
"

IL00149.CV5

Figure 3. Minimum Clearances

2. For side access remove the control panel, cooling coil
panel, or heating panel which are located on the same
side as the refrigerant, drain, and water connections.

3. Where the unit is suspended or mounted on the wall
using the mounting rails, the panel below the
blower/motor assembly can be removed for servicing.
In this case access to the coils must be from the side
access panels. See Fig. 3.

Bulletin 100-150 — Page 3

Position the return air box and filter near the unit allowing
at least one 90° bend in the return duct for proper acoustical
performance. Fig. 4 shows a typical horizontal attic
installation

The standard return duct is 10 feet (3 m) in length so it may
have to be cut to avoid bunching if the distance to the unit is
significantly less than 100 inches. If needed, up to two
return ducts can be coupled to make a 20-ft (6-m) duct. The
minimum length should be 6 feet (2 m). When given a
choice, maximize the distance and make at least one 90°
bend for the best sound attenuation.

Each unit is designed to fit into a small space where a
conventional unit could not be used. The 12-in. height
allows the unit to fit through joists or studs spaced at least
16-inches (406 mm) on center. If no access is provided, an
opening must be cut. It is suggested to use the opening
required for the return air box, especially in an attic
installation. The opening size for the return air box is listed
in Table 1. If the joists or studs are significantly less than 1 6
inches (406 mm) center-to-center or running the wrong
direction it would be necessary to cut and header the joists.

Table 1. Return Air Box Opening

Model Return Air Box Part No.

SDAH18 SD-01-18

Size of opening

inches (mm)

3

 20 ½

14

8

(365  521)

Secondary Drain Pan

Where an overflow of condensate could cause water
damage, a secondary drain pan MUST BE INSTALLED .
Place the drain pan on the mounting base, platform or angle
iron support frame. Be sure to allow enough room for the
drain line and connection (refer to Table 2). The unit should
be placed over the secondary drain pan. Use rubber pads for
isolation to raise the unit high enough in the secondary
drain pan for the drain line to clear the side.

Figure 4. Typical Horizontal Attic Installation, SDAH18

Bulletin 100-150 — Page 4

Table 2. Secondary Drain Pan

Unit Size Part No.

SDAH18 SD- 94

† NOTE — The drain fitting extends 7/8 inch (22 mm) beyond this dimension.

Dimensions

inches (mm)

40 x 22=

(1016 x 559)

Horizontal Platform Mounting

Mount the unit horizontally when vertical height is limited
such as in an attic or crawl space. It is easiest to mount the
unit on a platform but care must be taken to assure proper
drain line pitch.

The platform height must allow for proper pitch of the
condensate drain lines — at least ¼ inch drop per linear foot
(20 mm per meter). The platform can be built from a sheet
of ½ inch (13 mm) plywood and stud frame. Table 3 lists
the maximum horizontal drain line run for various framing
materials and still provide adequate drainage.

Table 3. Horizontal Dist ance of Drain Piping for
Different Framing Materials

Frame Lumber:

Max. Horizontal Run,
ft. (m)

2 x 4 2 x 6 2 x 8 2 x 10

18 (5) 26 (8) 34 (10) 42 (13)

CAUTION

DO NOT HANG UNIT FROM TOP OF
CABINET IF NOT USING MOUNTING RAILS
TO AVOID DAMAGING THE EQUIPMENT.

Use either four (4) chains or steel cables with 80 lbs. (36
kg) test strength to hang the unit. Use eyebolts and ‘J”
hooks as applicable to attach the chains or cables to the unit
and the ceiling.

Place the unit inside of the secondary drain pan as you
would for platform support with the angle iron supports
lengthwise under the secondary drain pan. Level the unit by
adjusting the length of the chains or cables.

If using the alternative method, hang the secondary drain
pan from the unit using self-tapping screws and metal straps
or wires. Adjust the straps or wires to pitch the secondary
drain pan toward the drain connection.

The platform size should be a minimum of 22 x 40 inches
(559 x 1016 mm).

Place secondary drain pan on platform and unit on top of
isolation pads inside of secondary drain pan. Be sure that
the unit is raised high enough in the drain pan to allow for
primary drain line condensate connection.

Figure 5. Typical Platform Installation

Horizontal Suspended Mounting

The unit can also be suspended from the ceiling or rafters.
The preferred method is to support the unit and the
secondary drain pan from underneath with angle iron
supports (see Fig. 6). As an alternative, the unit can be hung
with the mounting rails.

Figure 6. Typical Horizontal Suspension Mounting

Ceiling Mounting

If desired, the unit can be mounted flush to the ceiling (see
Fig. 7) using the optional mounting rails (SD–95). Remove
top screws from both sides of the unit. Align holes on
mounting rails with the holes on the unit. Fasten mounting
rails to the unit with the screws that were removed earlier.
Attach unit to a structural member. Suspend secondary
drain pain from the unit with metal straps or wires.

Joist

Ceiling

Mounting Rails

Unit

Metal Straps o r Wires

Figure 7. Typical Ceiling Mounting

IL00164.CV 5

Seconda ry Drain Pa

Vertical Rail Mounting

The unit can only be mounted in the vertical up-flow
configuration. The vertical rail mounting method is shown
in Figure 9. Mark hole pattern on wall and install stud
screws or lag screws (see Fig. 8).

To install the unit vertically, such as in a closet, basement,
or utility room, attach the mounting rails (SD-95) to the top
of the unit as explained previously. Screw or nail a
temporary board to the wall at the bottom of the location
where the unit will be mounted. The unit will rest on this
board during mounting. If the wall covering is not adequate
enough to hold the weight of the unit, use lag screws to
attach the rails to the structure. Use six (6) lag screws a
minimum of 3 inches (77 mm) long, which will be screwed
directly into a stud or structural member. If the wall
covering is sufficient, toggle screws may be used to mount
the unit. The board can be moved when the mounting of the
unit is completed.

DUCT CONNECTION

Supply Plenum

The standard supply plenum is a 7-inch (178-mm) diameter
duct, although this can be reduced to a 6-inch (152-mm)
diameter duct. The SDAH18 plenum adapter (SD-61-18)
provides a convenient connection to a 7 in (178-mm) duct.

Bulletin 100-150 — Page 5

on the unit. Mount the adapter with six (6) sheet metal
screws. See Figure 10.

Attach the plenum to the adapter by inserting it over the
collar. Use three (3) or four (4) equally spaced sheet metal
screws to secure the duct to the collar and then tape around
the seam with UL 181A aluminum tape. Then wrap the 1-in
fiberglass blanket duct insulation around the adapter and
seal with UL 181A aluminum tape.

The supply plenum also can be square or rectangular. The
inside dimensions of the duct must provide a minimum of
30 sq. in. (194 sq. cm.) of flow area, e.g. 5 x 6-in, 4 x 7 ½­in (125 x 150, 100 x 190 mm).

The supply plenum can be a 7-inch ID rigid round
fiberglass or a sheet metal duct with a minimum thickness
of 26 gage. Refer to a separate bulletin for the installation of
the ductwork.

Wall

Mounting Rail
(SD-95)

Unit

Mounting Board
(temporary)

Il00162.Cv5

Figure 9. Typical vertical Rail Mounting

A 6-in plenum can be used so long as a 7-in duct is attached
to the unit and is then reduced at least 4-ft from the unit.

To attach the plenum adapter to the unit, align the holes on
the adapter with the holes located around the supply outlet

Figure 10. Plenum Adapter Installation

Return Duct

The Heat Controller return air system has a single return
that includes the return air box with filter, the acoustical
flex return duct, and the return air adapter (refer to Fig. 4).
Multiple returns or extra long returns are possible so long as
the maximum pressure loss is not exceeded. The return
system is designed for a maximum static pressure drop of

0.15 inches of water (37 Pa) including the filter. The return
duct should have at least one 90 degree bend between the
unit and filter box to reduce sound transmission directly
from the unit.

Although Heat Controller only supplies a single return
system, the return system can be redesigned for multiple
returns. The return duct system is a conventional duct
design not high velocity; therefore, the return system may
be different; provided, the static pressure does not exceed

0.15 inches of water column and there is some form of
sound attenuation. Generally, this means sizing the duct for
a pressure loss of 0.05 inches of water column at the
required airflow and sizing the filter for a pressure dr op of

0.10 inches of water column at the required airflow. Sound

Bulletin 100-150 — Page 6

attenuation can be accomplished with fabricated duct board,
lined sheet metal, or acoustical flex (Part number SD-04-

18). For best attenuation, always have at least one 90
degree bend to eliminate direct line-of-site from the unit to
the return opening.

To install the return filter and grille, cut an opening for the
return box as specified in Table 1. If the joists or studs are
on 16 inch (410 mm) centers, there is no need to build a
frame to hold the return air box. Otherwise, it will be
necessary to construct a frame around the opening. Center
the return air box so the filter frame flange covers all the
gaps and make sure the flange is flush against the wall or
ceiling. Install the return air box against the frame using
nails or screws. Holes are provided in the return air box.
Use the four (4) ¼-inch (6.4 mm) holes. The other holes are
for mounting the filter grille.

Install filter frame into the return air box using four (4) nails
or screws. Insert filter and hold in place by rotating metal
clips. Close grille and secure with clips.

Connect the return air adapter to the unit u sing sheet metal
screws. Then attach the return duct to the adapter and to the
return air box using the supplied band. Tape the seams with
UL 181B duct tape.

PIPING

All piping must be in accordance with all local codes and
ordinances.

Condensate Lines

The primary drain pan condensate connection is a 1/2 inch
(13 mm) female pipe thread fitting and the secondary drain
pan connection is a 3/4 inch (19 mm) PVC socket fitting.
Elevate the unit so the condensate lines are pitched at least
¼ inch per lineal foot (20 mm per meter). Trap the
condensate line near the unit as shown in Figure 12. In
some cases it may be necessary to wrap the condensate line
near the unit with insulation to prevent water from
condensing on the outside of the pipe. In some climates or
locations it may be necessary to protect trap from freezing
in the winter.

Switch

Paper Fuse

Leads

Il00156.Cv5

Location of Paper Fuse

Indoor Terminal Block

1234 56 7

Condenser

R

Y

Switch

Il00157.CNV

Figure 13. Wiring Diagram for Paper Fuse

will dissolve and the switch will open causing th e outside
unit to shut down until it is serviced.

Also available is the Heat Controller Condensate U-Trap
which features a clear trap that is easy to visually inspect for
clogs. The U-Trap is designed for the Heat Controller
SDAH18 with a 2.5 inch (64mm) deep trap to handle the
higher static pressures. The U-Traps also feature easy to
remove clean-out caps and incorporate to tees to
accommodate any piping arrangement (Part No. SD-00924).

Do not trap the secondary drain line and do not terminate
line into the primary drain line. Run secondary drain line so
that any drainage will be immediately known without
causing damage to property. A typical location is to
terminate the secondary drain line above a windowsill so
that the drainage splashes on the window. This will serve as
an indicator that there is a problem with the primary drain.

An alternative method of notifying the homeowner about a
leakage problem is to use a paper fuse and micro switch.
See Fig. 13. Install a micro switch upside down on the side
of the secondary drain pan. Making sure that the switch is
open. Next, sandwich a paper fuse between the switch and
the bottom of the drain pan so that the switch is closed.
When water is present in the secondary drain pan, the fuse

Figure 12. Typical Condensate Trap

Refrigerant Connections

CAUTION: WHEN BRAZING, PURGE WITH
NITROGEN GAS TO PREVENT THE
FORMATION OF OXIDES.

The refrigerant lines are copper sweat connections. The
liquid line is 3/8 inch (9.5 mm) OD and the suction line is
5/8 inch (16 mm) OD. Refer to the condensing unit
manufacturer’s instruction for proper line sizing information
based on distance from condenser.

Install a liquid line filter drier as close to the coil as possible
to protect the evaporator from foreign object debris. For
troubleshooting purposes, especially for attic installations or
when using long line sets, an optional moisture indicating
sight glass should also be installed between the filter-drier
and expansion valve near the indoor unit.

Expansion Valve

The expansion valve is shipped loose inside the unit in the
blower section. Install the valve inside the unit as shown in
Fig. 14. Use the following steps when installing:

1. Remove plastic caps to external equalizer line and
distributor inlet.

Bulletin 100-150 — Page 7

Water Connections

If you are installing the hot water coil, remove the side coil
access panel. Slide the coil into the cabinet if not already
installed at the factory and reinstall the door panel. After
removing plugs in the inlet and outlet holes, caulk around
connections to prevent leakage.

Pump and pipe sizing should be based on proper flow rate.
Refer to Appendix A for water coil capacities based on flow
rate.

All water connections are 5/8 inches OD (16 mm) sweat
connections. Sweat the water connections, then fill the
system. Install a vent valve at the highest point and a drain
valve at the lowest point of the water system (refer to Fig.

17). Fill and bleed the air from the system. If unit is in an
unconditioned space care must be taken to prevent the water
from freezing. Use a glycol-water antifreeze solution with a
freezing point below the coldest temperature expected.

As an alternate to an anti-freeze solution, the water can be
continuously circulated to prevent freezing. If the coil will
not be used for an extended period of time during cold
temperatures, drain the system then flush with a glycol
solution.

2. Connect valve to distributor and tighten flare nut.

3. Connect external equalizer line and tighten flare nut.

4. Connect to the outlet the 3/8” (9.5 mm) OD copper
refrigerant fitting. Make sure the flare nut is tight.

5. After all lines have been connected, pressure-check the
connections by charging the system with 150 psig of
dry nitrogen and check for leaks at all connections.

Figure 14. Expansion Valve Location

Locate the bulb at the 12 O’clock position on a horizontal
straight section of the 5/8” (16 mm) suction line (see Fig

15). Attach the bulb to the tubing with the two straps that

are provided. For satisfactory expansion valve control, good
thermal contact between the bulb and the suction line is
essential.

Figure 15. Hot Water Coil Connection

Wiring

WARNING!

DISCONNECT ELECTRICAL SUPPLY BE­FORE WIRING UNIT TO PREVENT INJURY
OR DEATH FROM ELECTRICAL SHOCK.

All electrical wiring must comply with all local codes and
ordinances. Make electrical connection in accordance with
the wiring diagram shown in Fig. 18. Use a separate 1 ph ­230/208V – 60/50 Hz power supply with a 15 amp fuse or
breaker and appropriate wire gauge per local code. Refer to
bulletin 100-180 for more information on wiring the System
Interface Board (SIB).