Bryant 452W User Manual

Installation Instructions

452W

SIZE 90

Series E

GAS-FIRED AIR CONDITIONER

Important—Read before Installing

1. Check all local or other applicable codes for in
formation concerning proximity to property lines,
height above roof, obstructions, etc.

2. Be sure the power supply available (voltage,
frequency, and phase) corresponds to that
specified on the unit rating plate.

3. Check the electrical service provided by the
utility for the building to be sure that the service
capacity is sufficient to handle the load imposed
by this unit.

4. Refer to the regulations of the serving gas sup

plier and the local building, heating, plumbing,
or other codes in effect in the area in which in
stallation is to be made.

5. Refer to the dimensional drawing on page 2 for

location of electrical, gas, and chilled-water con
nections prior to setting the unit in place.

C^els: 39452D70

FIL

OP

DO NOl

REMOV

bri|ant

39452D80
2/15/73

I

GENERAL

Model 90-452W is a gas-fired air-cooled absorption

unit designed to satisfy the cooling needs of com
mercial and industrial buildings. This absorption unit
supplies chilled water for cooling with Bryant’s indoor

and outdoor coil assemblies.

Multiple Chillers and Cooling Coils

When it is planned to connect two or more chillers or
coils, additional piping and electrical information is
required and should be obtained from your Bryant
Distributor. When making multiple chiller in
stallations, it is recommended that only Models 452
and 452W be interconnected. Interconnection of sizes
60, 90, and 120 is permissible, but the use of other
model chillers with Models 452 and 452W in a
multiple system should be avoided.

Operation at Atmospheric Pressure

The chilled-water tank on this unit is vented to the
atmosphere; consequently, the chilled-water circuit
operates at atmospheric pressure. Therefore, con

ventional piping practices for a closed, pressurized
system do not apply for this unit.

NOTE: When the water chiller is piped to a boiler as

described below, the indoor coil operates at or near
atmospheric pressure when used for cooling; the in
door coil may be pressurized when it is used with the
boiler for heating.

Figure 1 - Model 90-452W Gas Air Conditioner

When this chiller is piped with a boiler to form a com

bination heating and cooling system, provisions must
be made for a positive shutoff between the chiller tank
and the boiler.

When the boiler is in operation, the^ chiller tank must
be bypassed. A sediment strainer must be installed at

the chiller tank inlet when a common pipe connects
the chiller tank and boiler.

When the chiller is in operation the boiler, of course,
should be bypassed.

Installation

Installation of the Model 90-452W, Series E Gas
Chiller unit consists of the following steps:

I. Locating and Mounting the Unit

II. Connecting Chilled-Water Lines

III. Making Electrical Connections

IV. Making Gas Connections

V. Chilled-Water System

VI. Checking the Unit Operation

VII. Adjusting Gas Input

VIII. Balancing the System

Each of the above steps is discussed in detail in this

instruction. Read the entire instruction before starting

the installation.

AIR OUT

Figure 2 - Dimensionai Drawing

RATiNGS AND PERFORMANCE

MODEL
Unit Rating Plate (Voltage-Hertz-Phase)
Cooling Capacity
Gas Input
Condenser Air Delivery
Chilled-Water Flow Rate (Nominal)
Max Head at Nominal Water Flow Ft Water
Electrical Input KW 2.5
Fan Motor (2) HP & SF

Voltage Hertz-Phase
Capacitor (370 Volts)

Hydraulic Pump Motor

Voltage-Hertz-Phase

Alternate Hydraulic Pump Motor HP & SF

Voltage-Hertz-Phase

Chilled-Water Pump HP & SF

Voltage-Hertz-Phase

Refrigerant

Amount
Total Solution

Bryant Sound Rating

Approximate Shipping Weight

Btuh
Btuh

CFM

GPM 18.75

mfd 10 7.5

HP & SF

Type

Lbs 18
Lbs

SRN

Lbs

200-60-1 230-60-1

90,000 90,000

246,000 246,000

10,000 10,000

37 37

1/2 & 1.0 1/2 & 1.0

200/230-60-1 200/230-60-1

1 & 1.25

200-60-1

1 & 1.25

200-60-1

1/3 & 1.35

200-230-60-1 200-230-60-1

R717

55
22

1317

COIL CLEANING
ACCESS PANEL

90-452W

Series E

1-1/2 & 1.25

208/230-60-1

1/3 & 1.35

4

-5

18.75

2.5

1 & 1.25

230-60-1

R717

18
55
22

1317

CONNECTIONS

MODEL
Unit Rating Plate (Voltage-Hertz-Phase)

**Maximum Line Length

Control Circuit Volts 24 24

External Power Available VA
Gas Supply Connection Size
Chilled-Water Supply (NPT)
Chilled-Water Return (NPT) Inches 1 FPT
Equalizer Line (NPT)

*If other than 75 °C copper conductor is used, determine size from unit ampacity and the National Electric Code.

Voltage drop of wire selected must be less than 2% of unit rated voltage.

**Length shown is for one way along the wire path from unit to service panel.

Unit Ampacity for Electrical Conductor Sizing Amps

*Min Branch Circuit Wire Size

Recommended Fuse Size

AWG No.

Amps 35 35

Ft

Inches 3/4 NPT 3/4 NPT
Inches

Inches 1-1/2FPT 1-1/2FPT

200-60-1

1-1/4FPT

90-452W
Series E

230-60-1

19.25 26.2
12 10

71 115

5 5

1-1/4FPT

1 FPT

— 2.

REFRIGERANT RESTRICTORS HIGH-PRESSURE

(CHILLER INLET) LIMIT SWITCH RECTIFIER

SECONDARY
HI-TEMP
LIMIT
SWITCH

AMBISTAT

PILOT
PRESSURE
SWITCH

REGULATOR

MANUAL
SHUT-OFF
VALVE

GAS VALVE

MAINTENANCE

LABEL

GENERATOR PILOT HI-TEMP LIMIT SWITCH

Figure 3 - Unit Front View With Access Panels Removed

VALVE C

S' .

IL

■

' V"

CHILLED­WATER
TANK

VALVE E

---------

PUMP
DISCHARGE ------­TANK

PUMP
HEATER

A72597

VALVE A

■ VALVE D

■

Figure 4 - Unit Left-Side View With

Access Panel Removed

— 3

HYDRAULIC SOLUTION
PUMP PUMPS
MOTOR

Figure 5 - Unit Right-Side View With

Access Panel Removed

I. LOCATING AND MOUNTING UNIT

The absorption unit is approved for outdoor in
stallation only and may be located at ground level or
on the roof. Consult local or other applicable codes for
information concerning proximity to property lines,
height above roof, obstructions, etc.

3. Leave sufficient clearance (6 inches minimum)
between unit base and roof for proper air cir
culation when installing unit on a roof. Use
precast concrete lintels or concrete blocks as
described in paragraph 2, or use steel beams.
Check local codes. Refer to NBFU code for In
stallation of Heat Producing Appliances.

A. Mounting Base

1. USE NONCOMBUSTIBLE MATERIALS.

2. Suggested types of mounting base for ground in
stallation ;

a. Precast concrete lintels. Use three lintels the

depth of unit, one each under right and left
end of unit, and one at center of unit.

b. Concrete blocks. Use one block at each corner

of unit plus blocks under the two long sides
midway between the corner blocks.

c. Concrete slab. Minimum thickness 4 inches.

II. CONNECTING CHILLED-WATER LINES

B. Clearances

1. Absorption unit should have a minimum clear
ance of 2 feet on all sides from any adjacent
obstruction.

2. Avoid locating the unit where hot condenser air
can impinge on nearby obstructions and mix with

the inlet air supply. The condenser air discharges
upward. The unit should be located outside of
the plumb line from any overhang when the
distance from the overhang to the top of the unit
is less than 7 feet.

Refer to “Multiple Chillers and Cooling Coils,” page 1; “Operation at Atmospheric Pressure,” page 1; and
“Chilled-Water System”, page 7, before making any chilled-water connections.

1

TABLE I

^Allowable Distance Between Coil & Chiller

Nominal

Pipe Size

(Inches)

1 30
1-1/4
1-1/2

NOTE; Values shown in Table I are for one direction only. The total length of pipe from chiller to coil and return would be double the values given.
The above table applies to single unit installations only.

A. Materials

NOTE: Black iron pipe must not be used for chilled-

water piping.

1. Piping
a. Polyethylene Plastic Pipe - use medium den

sity flexible pipe whose wall thickness
approximates Schedule 40 pipe (Commercial
Standard CS 255-63). Pipe must be virgin
plastic. Do not use pipe manufactured from
reclaimed plastic.

b. Copper—satisfactory substitute.

Polyethylene

Pipe

(Feet)

205
490

1. Multiply table values by two to obtain total
length of pipe from chiller to coil and return.

2. Length is measured along pipe path and
therefore includes vertical distance between
water coil and chiller.

3. Lengths shown in Table I are based on using a
total of eight galvanized wellhead elbows in en
tire water line (chiller to coil and return).
Lengths are predicated on use of a Bryant
matching water coil. For greater distances, use
larger pipe or add a pump. Consult your
Bryant Distributor for additional information.

Copper

Pipe

(Feet)

51
165
388

Galvanized

Pipe

(Feet)

54
220
492

c. Galvanized—satisfactory substitute.

2. Fittings
a. Galvanized—use when possible.

b. Brass—satisfactory substitute.

c. Nylon—satisfactory substitute.

B. Pipe Length and Diameter

Table I shows maximxom length of pipe of different
diameters that can be used between the pump
discharge and the coil inlet and still maintain
minimum allowable (design) water flow rate.

C. Insulation

1. Insulate supply and return lines separately.

2. Material should be of good quality and be
covered with a good vapor barrier. Armaflex or
equivalent is recommended.

Wall thickness; 1/2 inch.

D. Height of Coil above Absorption Unit

Practical coil elevation is limited only by the at

mospheric pressure supported hydraulic head.

— 4