35E Single-Duct Terminal Units
Variable Volume System
Installation and Start-Up Instructions
CONTENTS
Page
SAFETY CONSIDERATIONS ...................... 1
PRE-INSTALLATION.............................. 2
General ..........................................2
Warranty ......................................... 2
CONTROL ARRANGEMENTS....................3,4
INSTALLATION ................................. 4-6
Step 1 — Install Volume Control Box .............4
Step 2 — Make Duct Connections ................4
Step 3 — Install Sensors and Make Field
Wiring Connections — Electronic Analog
or DDC (Direct Digital Controls) ................4
CONTROL SET-UP ............................... 7
General ..........................................7
Set Points ........................................7
Field Adjustments of Minimum and
Maximum Airflow Set Points ................... 7
System Calibration of the Linear Averaging
Flow Probe.....................................7
PNEUMATIC CONTROLS .......................7-11
Preparation for Balancing (Control
Sequences 1102 and 1103)..................... 7
Balancing Procedure
(Control Sequences 1102 and 1103) ............ 9
• DIRECT ACTING THERMOSTAT,
NORMALLY OPEN DAMPER (Control
Sequence 1102)
• REVERSE ACTING THERMOSTAT, NORMALLY
CLOSED DAMPER (Control Sequence 1103)
Balancing Procedure
(Control Sequences 1104-1110) ............... 10
Preventative Maintenance .......................10
Pneumatic Control Troubleshooting............. 10
ANALOG CONTROLS ........................ 11-13
Balancing Procedures
(Control Sequences 2100-2105) ............... 11
Analog Control Troubleshooting ................13
ComfortID™ CONTROLS ..................... 13-21
Install Sensors and Make Field-Wiring
Connections .................................. 13
• GENERAL
• SUPPLY-AIR TEMPERATURE SENSOR
INSTALLATION
• SPACE TEMPERATURE SENSOR INSTALLATION
AND WIRING
• WIRING THE SPACE TEMPERATURE SENSOR
AND SET POINT ADJUSTMENT SLIDEBAR
• WIRINGTHECCNNETWORKCOMMUNICATION
SERVICE JACK
• PRIMARY AIR TEMPERATURE SENSOR
INSTALLATION
• INDOOR-AIR QUALITY SENSOR INSTALLATION
• INDOOR-AIR QUALITY SENSOR WIRING
• HUMIDITY SENSOR (Wall-Mounted)
INSTALLATION
Connect the CCN Communication Bus..........19
• COMMUNICATION BUS WIRE SPECIFICATIONS
• CONNECTION TO THE COMMUNICATION BUS
Water Valve Installation .........................19
ComfortID Start-Up.............................. 19
• GENERAL
• PRIMARY SYSTEM CHECK
• ComfortID CONTROL SYSTEM CHECK
CCN System Start-Up ........................... 20
VVT® CONTROLS ............................ 21-23
General .........................................21
• DIRECT DRIVE HIGH TORQUE ACTUATOR
• RELAY PACKAGE
• ADDITIONAL SENSOR INFORMATION
•THERMOSTATS
Thermostat Placement ..........................21
Wiring Requirements............................ 21
• CCN COMMUNICATIONS
• THERMOSTAT TO TERMINAL CONTROL BOX
Wiring Connections ............................. 22
VVT Configuration/Testing ...................... 23
Control Start-up................................. 23
• GENERAL
• PRIMARY SYSTEM CHECK
SAFETY CONSIDERATIONS
SAFETY NOTE
Air-handling equipment will provide safe and reliable
service when operated within design specifications. The
equipment should be operated and serviced only by authorized personnel who have a thorough knowledge of system operation, safety devicesand emergencyprocedures.
Good judgement should be used in applying any
manufacturer’s instructions to avoid injury to personnel
or damage to equipment and property.
Disconnect all power to the unit before performing maintenance or service. Unit may automatically start if power is
not disconnected. Electrical shock and personal injury
could result.
If it is necessary to remove and dispose of mercury contactors in electric heat section, follow all local, state, and federal laws regarding disposal of equipment containing
hazardous materials.
Manufacturer reserves the right to discontinue, or change at any time, specifications or designs without notice and without incurring obligations.
Book 3
Ta b 6 a
Catalog No. 533-530 Printed in U.S.A. Form 35E-2SI Pg 1 3-06 Replaces: 35E-1SI
PRE-INSTALLATION
General —
nal available with factory-installed pneumatic, analog electronic, Carrier Comfort Network® (CCN) or VVT®(variable volume and temperature) electronic control options that can be
used in conjunction with unit-mounted electric or hot water
heat options. Figure 1 shows the basic box. Figure 2 is an
example of a unit identification label.
STORAGE AND HANDLING — Inspect for damage upon
receipt. Shipping damage claims should be filed with shipper
at time of delivery. Store in a clean, dry, and covered location.
Do not stack cartons. When unpacking units, care should be
taken that the inlet collars and externally mounted components
do not become damaged. Do not lift units using collars, sensors
or externally mounted components as handles. If a unit is supplied with electric or hot water heat, care should be taken to
prevent damage to these devices. Do not lay uncrated units on
end or sides. Do not stack uncrated units over 6 ft high. Do not
manhandle. Do not handle control boxes by tubing connections
or other external attachments. Table 1 shows component
weights.
INITIAL INSPECTION — Once items have been removed
from the carton, check carefully for damage to duct connections, coils or controls. File damage claim immediately with
transportation agency and notify Carrier.
UNIT IDENTIFICATION — Each unit is supplied with a
shipping label and an identification label (Fig. 2).
INSTALLATION PRECAUTION — Check that construction
debris does not enter unit or ductwork. Do not operate the
central-station air-handling fan without final or construction
filters in place. Accumulated dust and construction debris
distributed through the ductwork can adversely affect unit
operation.
SERVICE ACCESS — Provide service clearance for unit
access.
CODES — Install units in compliance with all applicable code
requirements.
UNIT SUSPENSION — See Fig. 3 for unit suspension details.
The 35E is a single duct, variable volume termi-
Warranty — All Carrier-furnished items carry the standard
Carrier warranty.
No periodic preventative maintenance required, unless
called for specific control sequence.
Fig. 1 — 35E Single Duct Box (Sizes 4-16)
Fig. 2 — Unit Identification Label
Table 1 — 35E Unit Weights
35E
SIZE
4, 5, 6 14 18 23 32 19/20
7, 8 16 20 25 39 21/23
9, 10 21 25 30 44 28/30
12 26 30 35 56 35/38
14 34 38 43 65 44/49
16 38 42 47 75 50/55
22 65 69 74 91 82/90
DDC — Direct Digital Controls
NOTE: Data is based on the following conditions:
1. Unit casing is 22 gage.
2. Unit insulation is
3. Units rated with standard linear flow sensor.
LEGEND
UNIT ONLY
(lb)
1
/2-in. thick, 1.5-lb Tuf-Skin Rx™, dual density.
WITH PNEUMATIC
CONTROLS
(lb)
WITH DDC OR
ANALOG CONTROLS
(lb)
WITH ELECTRIC HEAT
CONTROLS
(lb)
WITH HOT WATER
(1 ROW/2 ROW) (lb)
2
FIELD SUPPLIED
HANDING WIRE
BRACKET
DETAIL
Fig. 3 — Typical Unit Suspension with Brackets
CONTROL ARRANGEMENTS
The 35E single-duct unit is offered with a wide variety of
factory-mounted controls that regulate the volume of air delivery from the unit and respond to cooling and heating load requirements of the conditioned space. Stand-alone controls will
fulfill the thermal requirements of a given control space. These
devices are available in both pneumatic and electronic arrangements. Carrier VVT® electronic controls and PIC (Product
Integrated Control) DDC (Direct Digital Controls) are communicating controls which are integrated with the building system.
The PIC controls are compatible with the CCN system. A number of DDC control packages by others are available for consignment mounting, as indicated.
Control offerings are:
35EA: Analog Electronic
35EC: PIC Direct Digital Electronic
35EP: Pneumatic
35EV: VVT Electronic (Gen. III or 3V™ controls)
35EN: None or DDC by others
Each control approach offers a variety of operating functions; a control package number identifies combinations of
control functions. The following listings contain the basic function arrangements for each control offering. Because of the
variety of functions available, circuit diagrams, operating
sequences, and function descriptions are contained in separate
Application Data publications. Refer to the specific control
publication for details.
CCN Control Arrangements — Carrier Comfort Net-
work® (CCN) controls are factory-installed in a control enclosure. Factory-mounted transformers are available as an option.
Thermostats are supplied separately as a field-installed accessory. Carrier Comfort Network control packages must be used
in combination with a thermostat. Thermostats are not
included in the CCN package.
4140: Cooling only
4141: Single-stage and 2-stage electric heat
4142: 3-stage electric heat
4143: On-Off hot water
4144: Proportional (floating) hot water heat
4145: Cooling only with supply return tracking
4147: Single-stage, 2-stage and 3-stage electric heat with
supply return tracking
4149: Proportional (floating) hot water with supply return
tracking
4150: Return air damper
CCN Thermostats (Ordered Separately)
Thermostat: 33ZCT56SPT: RT (room temperature) sensor,
with set point adjust and override.
Thermostat: 33ZCT55SPT: RT (room temperature) sensor,
with override only.
Thermostat: 33ZCT58SPT: Communicating room temperature sensor with LCD (liquid crystal diode), set point adjust,
fan control and occupancy override.
Thermostat: 33ZCT56CO2: RT (room temperature) and CO
sensor, with set point adjust and override.
Thermostat: 33ZCT55CO2: RT (room temperature) and CO
sensor, with override only.
VVT Electronic Control Arrangement — Va r i -
able volume and temperature (VVT) controls are factoryinstalled in a control enclosure. Factory-mounted transformers
are available as an option. Thermostats are supplied separately
as a field-installed accessory.
GEN. III CONTROL CODES AND DESCRIPTIONS
8200: Pressure dependent, cooling only
8201: Pressure dependent, cooling with 2-stage electric heat
8202: Pressure dependent cooling with on/off hot water heat
8206: Pressure independent, cooling only
8207: Pressure independent, cooling with 2-stage electric heat
8208: Pressure independent cooling with on/off hot water heat
8209: Variable air volume (VAV) pressure dependent unit
control zone (Monitor)
8210: Bypass controller, 2-in. wg transducer
3V CONTROL CODES AND DESCRIPTIONS
8220: Pressure dependent cooling only
8221: Pressure dependent cooling with 3-stage electric heat
8222: Pressure dependent cooling with on/off hot water heat
8223: Pressure dependent cooling with modulating hot water
heat
8224: Pressure dependent cooling with combination base-
board and 2-stage electric heat
8226: Pressure independent cooling only
8227: Pressure independent cooling with 2-stage electric heat
8228: Pressure independent cooling with on/off hot water heat
8230: Bypass control
Analog Electronic Control Arrangement —
Pressure independent control packages are available without
supplemental heat, with on/off hot water or electric heat, proportional hot water heat, or with cooling/heating automatic
changeover control.
2
2
3
All analog control arrangements include a standard linear
inlet flow sensor, 24-v transformer (optional), control enclosure and wall thermostat to match the control type.
2100: Heating control
2101: Cooling control
2102: Cooling with on/off electric heat control
2103: Cooling with on/off hot water heat control
2104: Cooling/heating automatic changeover control
2105: Cooling with proportional hot water heat control
Pneumatic Control Arrangement — All control
packages are pressure independent (unless otherwise noted)
and available with or without hot water heat, dual maximum
airflow, heating and cooling maximum airflow and dual minimum airflow. All control arrangements include a standard
linear inlet flow sensor.
1100 (Actuator only): DA-NC pressure dependent control
1101 (Actuator only): RA-NO pressure dependent control
1102 (Single function controller): DA-NO with or without hot
water or electric heat
1103 (Single function controller): RA-NC with or without hot
water or electric heat
1104 (Multi-function controller): DA-NO with or without hot
water or electric heat
1105 (Multi-function controller): DA-NC with or without hot
water or electric heat
1106 (Multi-function controller): RA-NO with or without hot
water or electric heat
1107 (Multi-function controller): RA-NC with or without hot
water or electric heat
1108 (Dual Maximum Control): DA-NO with or without hot
water or electric heat
1109 (Heating/Cooling Maximum Control): DA-NO with or
without hot water or electric heat
1110 (Dual Minimum Control): DA-NO with or without hot
water or electric heat
PNEUMATIC CONTROL LEGEND
DA: Direct-acting thermostat
RA: Reverse-acting thermostat
NO: Normally open damper position
NC: Normally closed damper position
The single function controller provides single functions, i.e.,
DA-NO. Multi-function controllers are capable of providing
DA-NO, DA-NC, RA-NC or RA-NO functions.
Direct Digital Electronic Control Arrangements (Field-Supplied) — Control packages are field-
supplied for factory mounting, unless otherwise noted. All
DDC control arrangements include a standard linear inlet flow
sensor, transformer to 24 volts and control enclosure.
Contact Carrier for detail about mounting field-supplied
controls.
NO CONTROL
0000: 35E box only
D000: 35E box with control box only (For units without
electric heat requiring a 24 v control transformer: the control
transformer must be ordered from the unit accessories list in
Quote Builder.)
D001: 35E box with control box and 24 v transformer
P000: 35E box without controls (for DA pneumatic controlled
heat unit)
P001: 35E box without controls (for RA pneumatic controlled
electric heat unit)
INSTALLATION
LOCK OUT AND TAG heater electrical disconnect before
working on this equipment. Otherwise, one leg of the 3-leg
heater remains energized. Electrical shock or personal
injury could result.
Step 1 — Install Volume Control Box
1. Move unit to installation area. Remove unit from shipping package. Do not handle by controls or damper
extension rod.
2. The unit has factory-installed brackets on unit as shown
in Fig. 3.
3. Suspend units from building structure with straps, rods,
or hanger wires. Secure the unit and level it in each direction. Note that reheat coil is in heavy end of unit.
Step 2 — Make Duct Connections
1. Install supply ductwork on unit inlet collar. Check that
air-supply duct connections are airtight and follow all
accepted medium-pressure duct installation procedures.
(Refer to Table 2 for pressure data.)
NOTE: To ensure proper equipment performance, it is
recommended that a length of rigid straight duct equal to
3 times the duct diameter be provided to the inlet.
2. Install the discharge duct. Where a multiple outlet connector is used on the box, connect appropriately sized
ductwork to the outlets. Use adapter caps to seal unused
outlets. Fully open all balancing dampers.
To ensure use of common-diameter air duct, coordinate
diameters of box inlet and multiple outlet collars. Insulate duct
as required.
Ninety degree elbows or tight radius flexible duct immedi-
ately upstream of inlet collar should be avoided.
Step 3 — Install Sensors and Make Field Wiring Connections — Electric Analog or DDC
(Direct Digital Controls) —
mensional submittals and control application diagrams for control specifications. All field wiring must comply with National
Electrical Code (NEC) and local requirements. Refer to the
wiring diagram on the unit for specific wiring connections.
A field-supplied transformer is required if the unit was not
equipped with a factory-installed transformer. See Fig. 4.
Single duct terminal units with electric heat are supplied
with a single point wiring connection in the heater control box.
All unit power is supplied through this connection. Models
with electric heat are factory equipped with a control transformer. See Fig. 5.
Wiring and unit ampacities are referenced in Tables 3A and
3B.
NOTE: Refer to wiring diagram attached to each unit for specific information on that particular unit. Units with 480-3-60
electric heater REQUIRE 4-wire, wye connected power.
units with 208/230 v, 3-phase heater can be connected with
3-wire power.
Unit airflow should not be set outside of the range noted in
Fig. 6. The minimum recommended airflow for units with electric heat must be at least 75 cfm per kW and not drop below the
minimum values listed in the performance data table. The maximum unit discharge temperature should not exceed 120 F.
Prevent air stratification by setting the discharge temperature
no more than 15 degrees above the room temperature.
Example: 90 F discharge in a 75 F room.
Refer to specific unit di-
4
Table 2 — 35E Basic Pressure Data
INLET
SIZE (in.)
CCN — Carrier Comfort Network® ∆ PS— Thedifferenceinstaticpressure
DDC — Direct Digital Controls
EAT — Entering Air Temperature
UL — Underwriters Laboratories ∆ VPS— Change in velocity pressure
*Minimums are for all except CCN controls, which may be lower. Minimum for DDC by
†A minimum 0.03 in. wg discharge static pressure is required to set the flow switch in the
**Maximum discharge temperatures with electric heat are set at 120 F by the National
CFM
(Area)
4 110 2.3 0.10 0.01 0.02 0.03 0.03 0.04 0.01
(0.09) 170 3†† 0.23 0.02 0.04 0.06 0.08 0.10 0.02
(0.14) 265 5†† 0.23 0.04 0.10 0.15 0.20 0.24 0.04
(0.20) 380 7.5†† 0.22 0.09 0.20 0.30 0.40 0.50 0.09
(0.27) 525 9.5†† 0.23 0.09 0.20 0.30 0.40 0.50 0.09
(0.35) 675 13†† 0.21 0.09 0.27 0.44 0.60 0.76 0.09
(0.44) 875 16†† 0.21 0.17 0.31 0.44 0.57 0.69 0.17
(0.55) 1075 21†† 0.20 0.10 0.31 0.50 0.69 0.89 0.10
(0.78) 1550 30†† 0.19 0.09 0.33 0.54 0.75 0.96 0.09
(1.07) 2125 36†† 0.17 0.10 0.31 0.49 0.68 0.86 0.10
(1.40) 2725 36†† 0.14 0.09 0.32 0.53 0.73 0.94 0.09
(2.63) 5200 36†† 0.16 0.09 0.43 0.74 1.05 1.36 0.09
230 3†† 0.43 0.03 0.07 0.11 0.15 0.18 0.03
5 170 3.5 0.09 0.02 0.04 0.06 0.08 0.10 0.02
360 5†† 0.43 0.08 0.18 0.27 0.36 0.45 0.08
100
6 240 4.9 0.09 0.04 0.08 0.12 0.16 0.20 0.04
520 7.5†† 0.42 0.17 0.38 0.57 0.75 0.94 0.17
140
7 330 6.8 0.09 0.04 0.08 0.12 0.16 0.20 0.04
710 9.5†† 0.41 0.17 0.37 0.55 0.73 0.91 0.17
190
8 440 9.1 0.09 0.04 0.12 0.19 0.25 0.32 0.04
925 13†† 0.39 0.17 0.51 0.82 1.13 1.43 0.17
240
9 550 11.3 0.08 0.07 0.12 0.17 0.22 0.27 0.07
1200 16†† 0.40 0.32 0.59 0.83 1.07 1.31 0.32
300
10 675 13.9 0.08 0.04 0.12 0.20 0.27 0.35 0.04
1450 21†† 0.36 0.17 0.56 0.91 1.26 1.62 0.17
425
12 1000 20.6 0.08 0.04 0.14 0.22 0.31 0.40 0.04
2100 30†† 0.34 0.17 0.60 0.99 1.37 1.76 0.17
580
14 1375 28.3 0.07 0.04 0.13 0.21 0.28 0.36 0.04
2900 36†† 0.31 0.19 0.57 0.92 1.26 1.60 0.19
750
16 1775 36†† 0.06 0.04 0.14 0.22 0.31 0.40 0.04
3700 36†† 0.25 0.17 0.59 0.97 1.35 1.73 0.17
1800
22 3300 36†† 0.07 0.04 0.17 0.30 0.42 0.55 0.04
7100 36†† 0.31 0.17 0.81 1.38 1.95 2.53 0.17
others is to be provided by the control’s provider.
electric heater.
Electric Code. Max kW shown assumes 55 F entering air and is limited by unit’s selected
MIN AIRFLOW ( Cfm)*
Cooling Only or
Cooling with Hot Water
55
85
50
or
0
75
or
0
110
or
0
140
or
0
185
or
0
240
or
0
290
or
0
420
or
0
580
or
0
740
or
0
1400
or
0
Electric
LEGEND
ELECTRIC HEAT**
MAX kW
Heat †
1800
AT 5 5 F EAT
1.1 0.02 0.00 0.00 0.01 0.01 0.01 0.00
55
1.7 0.02 0.00 0.01 0.02 0.02 0.03 0.00
85
2.1 0.02 0.01 0.01 0.02 0.03 0.03 0.01
110
2.9 0.02 0.01 0.01 0.02 0.03 0.04 0.01
140
3.9 0.02 0.01 0.02 0.03 0.05 0.06 0.01
190
4.9 0.02 0.01 0.02 0.03 0.04 0.05 0.01
240
6.2 0.02 0.01 0.02 0.04 0.05 0.07 0.01
300
8.7 0.01 0.01 0.02 0.04 0.06 0.07 0.01
425
11.9 0.01 0.01 0.02 0.04 0.05 0.06 0.01
580
15.4 0.01 0.01 0.02 0.04 0.06 0.07 0.01
750
36†† 0.02 0.01 0.05 0.09 0.13 0.16 0.01
from inlet to discharge with damper
fully open
Velocity Press
(∆ VPS)
MINIMUM INLET STATIC PRESSURE (Unit and Heat Pressure Drop)
Basic Unit
Basic + 1 Row
(∆ PS)
Coil (∆ PS)
voltage, phase, max capacity and design (see Electrical Data in the Product Data catalog). Min cfm for electric heat is based on UL/ETL listings. (Diffuser) performance will
likely be poor at this low flow rate.) The ASHRAE (American Society of Heating, Refrigeration and Air Conditioning Engineers) Handbook of Fundamentals does not recommend a discharge temperature exceeding 90 F for satisfactory air mixing and comfort.
††Max. kW is limited by design.
NOTES:
1. To obtain Total Pressure (Pt), add the Velocity Pressure for a given cfm to the Static
Pressure drop (∆ PS) of the desired configuration.
Example: Pt for a Size 8 Basic Unit at 925 cfm = 0.39 + 0.17 = 0.56
2. The electric heat max kW is based on 3 phase power. For more details, refer to the air
terminal selection program.
Basic + 2 Row
Coil (∆ PS)
Basic + 3 Row
Coil (∆ PS)
Basic + 4 Row
Coil (∆ PS)
Basic +Heater †
(∆ PS)
Table 3A — 35E Heater Power Wiring and
Fuse Sizing (Single Phase, 60 Hz)
HEATER
SIZE (kW)
10.0 34,130 83.3 2 41.7 6 36.1 6
11.0 37,130 91.7 2 45.8 6 39.7 6
12.0 40,956 100.0 1 50.0 6 43.3 6
AWG — American Wire Gage
FLA — Full Load Amps
*Values based on 75 C copper wire.
BTUH
0.5 1,707 4.2 14 2.1 14 1.8 14
1.0 3,413 8.3 14 4.2 14 3.6 14
2.0 6,826 16.7 10 8.3 14 7.2 14
3.0 10,239 25.0 8 12.5 12 10.8 14
4.0 13,652 33.3 8 16.7 10 14.4 12
5.0 17,085 41.7 5 20.8 10 18.1 10
6.0 20,478 50.0 5 25.0 8 21.7 10
7.0 23,898 58.3 4 29.2 8 25.3 8
8.0 27,304 66.7 4 33.3 8 28.9 8
9.0 30,717 75.0 3 37.5 6 32.6 8
LEGEND
120 V 208/240 V 277 V
Heater
FLA
AWG *
Heater
FLA
AWG *
Heater
FLA
AWG *
Table 3B — 35E Heater Power Wiring and
HEATER
SIZE (kW)
0.5 1,707 1.4 14 0.6 10
1.0 3,413 2.8 14 1.2 10
2.0 6,826 5.6 14 2.4 10
3.0 10,239 8.3 14 3.6 10
4.0 13,652 11.1 14 4.8 10
5.0 17,085 13.9 12 6.0 10
6.0 20,478 16.7 10 7.2 10
7.0 23,898 19.4 10 8.4 10
8.0 27,304 22.2 10 9.6 10
9.0 30,717 25.0 8 10.8 10
10.0 34,130 27.8 8 12.0 10
12.0 40,956 33.3 8 14.4 12
14.0 47,782 38.8 6 16.8 12
16.0 54,608 44.4 6 19.2 10
18.0 61,434 50.0 6 21.6 10
20.0 68,260 55.5 4 24.0 10
22.0 75,086 61.1 4 26.4 8
24.0 81,912 66.6 4 28.8 8
26.0 88,738 72.3 3 31.3 8
28.0 95,564 77.8 3 33.7 8
30.0 102,390 83.4 2 36.1 6
32.0 109,216 89.0 2 38.6 6
34.0 116,042 94.5 1 41.0 6
36.0 122,868 100.1 1 43.4 6
LEGEND
AWG — American Wire Gage
FLA — Full Load Amps
*Recommended minimum wire size.
5
Fuse Sizing (3 Phase, 60 Hz)
BTUH
208 V 480 V
Heater FLA AWG* Heater FLA AWG*
L1
120VAC
208VAC
240VAC
277VAC
CLASS II
TRANSFORMER
(OPTIONAL)
ANALOG OR DDC
CONTROLLER
GROUND
24VAC
BLU
YEL
24 VAC
POWER
LEGEND
DDC — Direct Digital Controls
Field Wiring
Factory Wiring
NOTE: Drawing is typical — refer to actual unit wiring diagram
for details.
Fig. 4 — Wiring of Optional Factory-Mounted
Transformer
10000
8000
6000
4000
7250
3709
2840
2000
1000
CFM
800
600
400
200
100
80
60
SIZE 22
SIZE 16
SIZE 14
SIZE 12
SIZE 10
SIZE 9
SIZE 8
SIZE 7
E 6
SIZ
SIZE 5
SIZE 4
2086
1449
1174
927
710
522
362
232
40
20
10
0.01
.05
.03
VOLTS (ANALOG CONTROLS)
0.1
FLOW PROBE IN.WG
0.3 0.5
1
Fig. 6 — Linear Probe CFM vs Pressure Signal Graph
CFM AT ONE INCH SIGNAL
LEGEND
AFS — Airflow Switch
DDC — Direct Digital Controls
NOTE: Drawing is typical of 480V,
3-phase, 4-wire heater and control.
Refer to actual unit wiring diagram.
Fig. 5 — Typical Power Connections for 35E Units with 3-Stage Electric Heat
ANALOG
OR DDC
CONTROLLER
SEPARATE
CONTROL
ENCLOSURE
6
CONTROL SETUP
General —
terminal is designed to supply a varying quantity of cold primary air to a space in response to a thermostat demand. Some
units have reheat options to provide heating demand requirements as well. Most VAV terminals are equipped with pressure
compensating controls to regulate the response to the thermostat independent of the pressure in the supply ductwork.
To balance the unit, it is necessary to set both the maximum
and minimum set points of the controller. The many types of
control options available each have specific procedures required for balancing the unit.
The 35E single-duct VAV (variable air volume)
Set Points — Maximum and minimum airflow set points
are normally specified for the job and specific for each unit on
the job. Where maximum and minimum airflow levels are not
specified on the order, default values are noted on unit ID label.
Field Adjustment of Minimum and Maximum
Airflow Set Points — Each 35E unit is equipped with a
flow probe that measures a differential pressure proportional to
the airflow. The relationship between flow probe pressures and
cfm is shown in the Linear Probe CFM vs Pressure Signal
Graph (Fig. 6). This chart is attached to each unit.
System Calibration of the Linear Averaging
Flow Probe — To achieve accurate pressure independent
operation, the velocity sensor and linear averaging flow probe
must be calibrated to the controller. This will ensure that airflow measurements will be accurate for all terminals at system
start-up.
System calibration is accomplished by calculating a flow
coefficient that adjusts the pressure fpm characteristics. The
flow coefficient is determined by dividing the flow for a given
unit (design air volume in cfm), at a pressure of 1.0 in. wg differential pressure, by the standard pitot tube coefficient of
4005. This ratio is the same for all sizes if the standard linear
averaging probe is used.
Determine the design air velocity by dividing the design air
volume (the flow at 1.0 in. wg) by the nominal inlet area
(sq ft). This factor is the K factor.
Carrier inlet areas are shown in the table below. The design
air volume is also shown in this table. It can be determined
from this table that the average design air velocity for 35E units
is equal to 2656 fpm at 1.0 in. wg.
UNIT SIZE 35E 04 05 06 07 08 09
INLET
DIAMETER
AIRFLOW (Cfm)
AT 1 i n. w g
INLET AREA
(sq ft)
.
35EUNITSIZE1012141622
INLET DIAMETER 10.0 12.0 14.0 16.0 16 x 24
AIRFLOW (Cfm)
AT 1 i n. w g
INLET AREA
(sq ft)
NOTE: For Carrier ComfortID™ terminals, all flow sizes are normalized using a single Probe Multiplier (PMF) for all sizes equal to
2.273.
4.0 5.0 6.0 7.0 8.0 9.0
232 362 502 710 927 1174
0.087 0.136 0.196 0.267 0.349 0.442
1449 2086 2840 3709 7250
0.545 0.785 1.069 1.396 2.640
Record the information on a performance sheet (see
Fig. 7). This will provide a permanent record of the balancing information.
• installation location information
•boxsize
• cooling minimum airflow (cfm) limit
• cooling maximum airflow (cfm) limit
• reheat (cfm) limit (if applicable)
• heating minimum airflow (cfm) limit (if applicable)
• heating maximum airflow (cfm) limit (if applicable)
• calibration gain (after balancing)
• set points
PNEUMATIC CONTROLS
Preparation for Balancing (Control Sequences
1102 and 1103)
1. Inspect all pneumatic connections to assure tight fit and
proper location.
2. Verify that the thermostat being used is compatible with
the control sequence provided (direct acting or reverse
acting).
3. Check main air pressure at the controller(s). The main air
pressure must be between 15 psi and 25 psi. (If dual or
switched-main air pressure is used, check the pressure at
both high and low settings.) The difference between
“high” pressure main and “low” pressure main should be
at least 4 psi, unless otherwise noted, and the “low” setting difference should exceed 15 psi.
4. Check that the unit damper will fail to the proper position
when main air pressure is lost. Disconnect the pneumatic
actuator line from the velocity controller and observe the
VAV damper position. The damper should fail to either a
normally open position (indicator mark on shaft end is
horizontal) or a normally closed position (indicator mark
on shaft end is vertical).
5. Check that there is primary airflow in the inlet duct.
6. Connect a Magnehelic gage, inclined manometer or other
differential pressure measuring device to the balancing
taps provided in the velocity probe sensor lines. The
manometer should have a full scale reading of 0.0 to
1.0 in. wg. The high pressure signal is delivered from the
front sensor tap (away from the valve), and the low pressure signal is delivered from the back line (near the
valve). The pressure differential between high and low
represents the amplified velocity pressure in the inlet
duct.
7. Read the differential pressure and enter the Linear Averaging Probe Chart to determine the airflow in the terminal
unit. This chart is shown in Fig. 6 and is also attached to
the side of each unit. For example, a differential pressure
of 0.10 in. wg for a size 8 unit yields an airflow of
275 cfm.
Volume controllers for 35EP units are shown in Fig. 8-10.
Identification for each controller is shown in Table 4.
7
AIR TERMINAL PERFORMANCE SHEET
JOB NAME ______________________________________________
JOB LOCATION __________________________________________
CUSTOMER _____________________________________________
ENGINEER ______________________________________________
BUILDING LOCATION/FLOOR ______________________________
BUS NUMBER ___________________________________________
CONTROL SET POINTS
Tag
Number
Zone
Address #
Box
Size
(in./cfm)
Cooling
(cfm)
min max min max Type Btu min max min max mult.
Reheat
cfm
Heating
(cfm)
Heat kW Occupied Unoccupied
Calibration
Gain
Fig. 7 — Air Terminal Performance Sheet
8
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