Terra Universal WhisperFlow 6601-24A-UR-220 User manual

Terra Universal Product Manual Document No. 1788-49
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
TABLE OF CONTENTS
1. General Information ................................................................................................................................................................... 3
1.1 Part Numbers Covered by this Manual ................................................................................................................................... 4
2. Safety........................................................................................................................................................................................... 5
3. Start-Up ....................................................................................................................................................................................... 6
3.1 Installation............................................................................................................................................................................... 6
3.2 WhisperFlow® Fan Filter Units ............................................................................................................................................... 7
3.3 Reverse Air-Flow Room-Side WhisperFlow® Fan Filter Units................................................................................................ 9
3.4 Smart® WhisperFlow® with EC Motor.................................................................................................................................. 11
3.4.1 120V and 220V Configurations........................................................................................................................................ 12
3.4.1.1 120V Configuration (default)....................................................................................................................................... 12
3.4.1.2 220V Configuration..................................................................................................................................................... 12
3.5 EC Motor Control Card.......................................................................................................................................................... 14
3.5.1 Control Modes ................................................................................................................................................................. 15
3.5.2 Test Probe Terminals ...................................................................................................................................................... 16
3.5.3 Control Card Electrical Specifications.............................................................................................................................. 17
4. Cleaning .................................................................................................................................................................................... 18
4.1 Room-Side Filter Replacement (BIBO compatible)............................................................................................................... 18
4.2 Top-Side Filter Replacement ................................................................................................................................................ 19
5. Wiring Diagrams....................................................................................................................................................................... 21
6. Testing....................................................................................................................................................................................... 23
7. Troubleshooting....................................................................................................................................................................... 23
8. Replacement Parts................................................................................................................................................................... 24
9. Accessories .............................................................................................................................................................................. 25
10. Warranty....................................................................................................................................................................................26

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
1. General Information
This manual documents the operational guidelines for Terra Universal’s Standard WhisperFlow®, Smart® WhisperFlow® EC
(Electronically Commutated) Motor, Narrow WhisperFlow®, WhisperFlow® Reverse-Flow and Smart® WhisperFlow® Reverse-
Flow fan filter units.

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
1.1 Part Numbers Covered by this Manual
Fan Filter Unit Models
WhisperFlow® Room-Side
Replaceable
WhisperFlow®
Standard
Smart® WhisperFlow® WhisperFlow® Reverse-Flow
6601-24A-UR-220
6601-24-U-220
6601-24B-UR-EC
6601-24-UVSS
6601-24A-UR
6601-24-U
6601-24B-HRSS-EC
6601-24-UVFSS
6601-24A-HRSS-220
6601-24-HSS
6601-24B-HR-EC
6601-24-UV-220-CE
6601-24A-HR-220
6601-24-H2
6601-24A-USS-EC
6601-24-UV-220
6601-24A-HR
6601-24-H-NC
6601-24A-U-EC
6601-24-UV
6601-24-URS-220
6601-24-H-CA
6601-24A-HSS-EC
6601-24-HVSS
6601-24-HRSS
6601-24-H-220
6601-24A-H2-EC
6601-24-HVF-220
6601-23A-UR-220
6601-24-H
6601-24A-H-EC-CA
6601-24-HVF
6601-23A-UR
6601-23-U-220-CE
6601-24A-H-EC
6601-24-HV-220-CE
6601-23A-HRSS-220
6601-23-U-220
6601-23B-URSS-EC
6601-24-HV-220
6601-23A-HRSS
6601-23-U
6601-23B-UR-EC
6601-24-HV
6601-23A-HR-220
6601-23-HSS
6601-23B-HR-EC
6601-23-UVSS
6601-23A-HR
6601-23-H2
6601-23A-USS-EC
6601-23-UVFSS
6601-22A-UR-220
6601-23-H-CA
6601-23A-U-EC
6601-23-UV-220-CE
6601-22A-UR
6601-23-H-220
6601-23A-HSS-EC
6601-23-UV
6601-22A-HRSS-220
6601-23-H
6601-23A-HRSS-EC
6601-23-HVF-220
6601-22A-HRSS
6601-22-U-220-CE
6601-23A-H-EC-CA
6601-23-HVF
6601-22A-HR-220 6601-22-U-220 6601-23A-H-EC 6601-23-HV-220-CE
6601-22A-HR 6601-22-U 6601-22B-URSS-EC 6601-23-HV-220
6601-22-HSS-220
6601-22B-UR-EC
6601-23-HV
Narrow WhisperFlow®
6601-22-HSS
6601-22B-HR-EC
6601-22-UVSS
6601-1648-H-220
6601-22-H-CA
6601-22A-USS-EC
6601-22-UVFSS
6601-1648-H
6601-22-H-220
6601-22A-U-EC
6601-22-UV-220-CE
6601-1636-HS
6601-22-H
6601-22A-H-EC-CA
6601-22-UV-220
6601-1636-H-220-CE
6601-22A-H-EC
6601-22-UV
6601-1636-H-220
Ducted Filtered
Diffusers
6601-22-HVF-220
6601-1636-H
6601-24-HDR
Smart® WhisperFlow® Reverse-Flow
6601-22-HVF
6601-1624-HS-220
6601-24-HD
6601-24A-UVSS-EC
6601-22-HV-220-CE
6601-1624-HS
6601-23-HDR
6601-24A-HV-EC
6601-22-HV-220
6601-1624-H-220-CE
6601-23-HD
6601-23A-UVSS-EC
6601-22-HV
6601-1624-H-220
6601-22-HDR
6601-23A-HV-EC
6601-22B-HVR
6601-1624-H 6601-22-HD 6601-22A-UVSS-EC 6601-22B-HVR-220
6601-22A-HV-EC 6601-24B-HVR
6601-24B-HVR-220

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
2. Safety
To reduce the risk of fire, electric shock, or injury to persons, observe the following:
•Do not use this unit for anything other than the intended manner of the manufacturer. Contact the manufacturer for
additional clarification.
•Before servicing the unit, or replacing a filter, switch power to OFF at the service panel and lock it to prevent
accidental power activation. When the panel cannot be locked, securely fasten a prominent warning device, such as a
tag, to the service panel.
•When the removal/disconnection of either filter is required due to service or component replacement, the
replacements are to be remounted as previously installed.
•Qualified person(s) must install the unit and configure the electrical wiring adhering to all applicable codes and
standards, which includes fire-rated construction. All metal components must be properly grounded.
•Do not damage or interfere with electrical wiring and other hidden utilities when cutting or drilling into the wall or
ceiling.
•Check the ECM unit’s supply cord for damage, if it is damaged it must be replaced by the manufacturer, its service
agent, or similarly qualified persons to avoid a hazard.
Critical Operation Conditions
•The filter media is extremely sensitive and can damage easily. The screen only protects against an accidental ‘touch’
of the filter media. Avoid touching and damaging the HEPA filter because the warranty will void.
•Never place anything on the filter. Always place filter on its side to avoid damage.
Proprietary Notice
Safety Notice
This manual pertains to proprietary devices manufactured by
Terra Universal, Inc. Neither this document nor any portion of
it may be reproduced in any way without prior written
permission from Terra Universal.
A thorough familiarity with all operating guidelines is essential to safe operation of
the product. Failure to observe safety precautions could result in poor
performance, damage to the system or other property, or serious bodily injury or
death. The following symbols are intended to call your attention to two levels of
hazard involved in operation.
Terra Universal makes no warranties applying to information
contained in this manual or its suitability for any implied or
inferred purpose. Terra Universal shall not be held liable for
any errors this manual contains or for any damages that
result from its use.
CAUTION
Cautions are used when failure to observe instructions could result in
significant damage to equipment.
WARNING
Warnings are used when failure to observe instructions or precautions
could result in injury or death.
The information presented here is subject to change without notice.
CAUTION

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
3. Start-Up
3.1 Installation
The fan filter unit is designed to fit on top of a Terra Laminar Flow Hood or standard clean room ceiling grid. It includes 1/4-
20 thread holes on corners for guy-wire suspension. Room-side replaceable filters are packaged separately for jobsite
installation by others.
1. Remove all packaging material from the shipping box
(Figure 1).
2. Perform a thorough visual inspection to ensure no
damage has occurred during shipping. Check that
there are no visible dents or penetrations on the filter
face and grille. If damage is discovered, contact the
freight company to file a damage claim immediately.
3. Remove the pre-filter and manually rotate the fan
wheel to make sure it does not come in contact with
any stationary parts and that there are no visible
loose screws or bolts obstructing the wheel’s
rotation.
4. Verify unit is sanitary for cleanroom placement.
5. Optional: fasten the eyebolts into each corner of the
lid assembly.
6. Lift the unit into the ceiling and position onto the
ceiling grid. If the grid is not secured, fasten to an
engineered support system with chain, s-hooks and
eyehooks (usually supported with wires).
7. Confirm fan dimensions are aligned with grid
dimensions.
8. Raise the unit and secure with support system
method suspended from a structural support bracing.
a. Minimum clearance of 1 foot (including
fixtures, ducts and pipes) on all sides and
at least 2 feet of vertical clearance between
the FFU inlet and ceiling for proper air
supply.
9. Connect the 4-pin power plug to the unit, set the
speed switch to the desired position (units are
shipped from the factory with the speed switch set to medium), and turn on the external power switch. With
power applied, the fan will rotate, and filtered air will exit the HEPA filter.
Note: After completing the Initial Setup, validation may be performed by a third-party testing service for HEPA filter integrity (leak-
testing), Air Changes per Hour and particle counter measurements to verify ISO 5 particle levels. Third-party testing should take
place within the intended cleanroom or another controlled environment to ensure an accurate evaluation of its performance.
Figure 1: Unboxing
Figure 2: Hanger Supports

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
3.2 WhisperFlow® Fan Filter Units
The WhisperFlow® fan filter unit has a 3-speed switch (low, medium, high) with a ¼ Hp permanent split capacitor motor.
The internal baffling plate and diffuser panel provide quiet uniform air flow across the filter face. FFU includes permanently-
lubricated bearings, factory balanced forward-curved blower wheel, ¼-20 thread holds on corners for guy-wire suspension,
and a filter membrane constructed from micro-glass. FFU uses FDA-approved silicon sealant and a 30% ASHRAE rated
MERV 7 pre-filter, 20” x 20” x 1”. The unit uses standard UL 900 filters and is tested to IEST recommended standards.
Room-side replaceable filter models feature fire retardant phosphorous free polyurethane gel-sealant to seat against a
knife-edge on the fan housing and easy-open clips for fast filter replacement from the room side without breaching the
cleanroom ceiling. The low profile design is ideal for cleanrooms with limited ceiling space.
There is challenge port fitting for a 3/8”-diameter challenge port, which can be used to take differential pressure
measurements to monitor filter performance or insert aerosols for leak-test certification. Port is capped when not in use.
PRODUCT DIMENSIONS
Nominal Unit
Size (ft.)
Active Filter
Area (sq. ft.) W (in) L (in) H (in)
Weight
(lbs.)
2’ x 4’
7.2’
23.63”
47.56”
12.60”
71
2’ x 4’ (RSR) 5.2’23.63” 47.63” 14.66” 71
2’ x 3’
5.3’
23.63”
35.56”
12.60”
53
2’ x 3’ (RSR)
3.7’
23.63”
35.63”
14.66”
53
2’ x 2’ 3.4’ 23.63” 23.56” 12.60” 44
2’ x 2’ (RSR)
2.2’
23.63”
23.63”
14.66”
44

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
WHISPERFLOW® FFU ELECTRICAL DATA
Nominal Unit
Size (ft.) Filter Motor HP Voltage Full Load Amps Frequency (Hz)
Power Consumption (Watts)
HIGH
MED
LOW
2’ x 4’
HEPA
1/4
120
3.8
60
420
380
360
2’ x 4’
HEPA
1/4
208-230/240
1.6/1.8
60/50
380
310
240
2’ x 4’
HEPA (RSR)
1/4
120
3.8
60
420
380
360
2’ x 4’
HEPA (RSR)
1/4
208-230/240
1.6/1.8
60/50
380
310
240
2’ x 4’
ULPA
1/4
120
3.8
60
440
425
415
2’ x 4’
ULPA (RSR)
1/4
120
3.8
60
440
425
415
2’ x 3’ HEPA 1/4 120 3.8 60 330 300 285
2’ x 3’
HEPA
1/4
208-230/240
1.6/1.8
50/60
300
270
230
2’ x 3’ HEPA (RSR) 1/4 120 3.8 60 310 290 250
2’ x 3’
HEPA (RSR)
1/4
208-230/240
1.6/1.8
50/60
300
270
230
2’ x 2’
HEPA
1/4
120
3.8
60
300
250
230
2’ x 2’
HEPA
1/4
208-230/240
1.6/1.8
50/60
230
190
180
2’ x 2’
HEPA (RSR)
1/4
120
3.8
60
320
235
200
2’ x 2’
HEPA (RSR)
1/4
208-230/240
1.6/1.8
50/60
230
190
180
Notes:
•Performance tested in accordance with the (ANSI/AMCA 210-07), (ANSI/ASHRAE 51-07) test standards for CertifiedAerodynamic
Performance Rating.
•Sound levels were measured with unit installed in a gasketed ceiling, in a standard room. Sound levels in dB were measured at a distance
of 12 inches from the filter face, with the unit set to produce 90 fpm average face velocity. (Note that data is for a clean filter only. If fan
speed is increased to compensate for filter loading the noise level will increase.)
•The unit set to produce 90 fpm average face velocity.
•All data is based on a unit with a 1” pre-filter and clean filter. Results will vary depending on filter media and ductingused.
•90 fpm values are based on active filter face area.
•Heat Gain: BTU = Watts x 3.413
•Units tested 2019
WHISPERFLOW® FFU PERFORMANCE DATA
Nominal Unit Size (ft.) Filter Sound (dB) @90FPM
AIR FLOW (CFM)
HIGH
MED
LOW
2’ x 4’
HEPA
49
800
720
590
2’ x 4’ HEPA (RSR) 49 800 720 590
2’ x 4’
ULPA
49
660
640
580
2’ x 4’
ULPA (RSR)
49
660
640
580
2’ x 3’
HEPA
49
675
630
560
2’ x 3’
HEPA (RSR)
49
600
560
540
2’ x 2’
HEPA
49
450
440
420
2’ x 2’
HEPA (RSR)
49
360
330
300

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
3.3 Reverse Air-Flow Room-Side WhisperFlow® Fan Filter Units
The exhaust flow fan filter unit converts any room into a negative pressure isolation/containment room with a HEPA filter
that is 99.99% efficient at 0.3µm particle diameter. The unit mounts into the ceiling bay with ¼-20 UNC threaded inserts
available on the corners for guy-wire suspension. The MERV 7 filter is 30% ASHRAE rated with an FDA-approved acrylic
urethane sealant that prevents air leakage from the inside housing. There is a removable yellow power cord with a 4-pin
connector that provides easy installation to Terra cleanrooms. This connector may be used with an optional wall plug
adapter or may be removed entirely to hard-wire the FFU. The optional duct collar attachment allows connection to
ducting system for safe exhaust outside of room.
The unit consists of a ¼ HP, thermally protected, variable speed motor that provides precise, fully adjustable airflow and
drives a backward-curved centrifugal blower. The dust collection pan collects particles that fall off the outside of the filter to
prevent them from being reintroduced into the surrounding environment. Air is drawn into the unit through the dust
collection pan and exhausted out through the blue MERV 7 filter. The MERV 7 filter protects against dust and debris from
falling into the impellor. The motor is controlled by an electrical speed dial control and this dial can function as ON/OFF for
the blower starting from high to low flow rates. The dust collector pan can integrate with bag-in/bag-out (BIBO) systems
and is easily removed for cleaning or maintenance.
Figure 3: WhisperFlow® Reverse-Flow FFU

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
REVERSE AIR-FLOW WHISPERFLOW® PERFORMANCE DATA
Nominal Unit Size (ft.)
Filter
Sound (dB) @90FPM
AIR FLOW (CFM) @ Max. Speed
2’ x 2’
HEPA (RSR)
60
387 CFM
2’ x 4’
HEPA (RSR)
60
353 CFM
REVERSE AIR-FLOW WHISPERFLOW® ELECTRICAL DATA
Nominal Unit Size (ft). Filter Motor HP Voltage Full Load Amps Frequency (Hz)
Power Consumption
(Watts)
2’ x 2’
HEPA
¼
115V
1.35
60
160
2’ x 2’
HEPA
¼
230V
0.66
50/60
125/170
2’ x 4’
HEPA
¼
115V
1.35
60
160
2’ x 4’
HEPA
¼
230V
0.66
50/60
125/170
PRODUCT DIMENSIONS
Nominal Unit Size (ft.) Active Filter Area (sq.ft)
W (in)
L (in)
H (in)
Weight (lbs.)
2’ x 2’ (RSR)
2.2’
23.625”
23.625”
17.975”
40
2’ x 4’ (RSR)
5.2’
47.625”
23.625”
17.975”
60

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
3.4 Smart® WhisperFlow® with EC Motor
The Smart® WhisperFlow® has an electronically commutated (EC) brushless motor that allows for quiet, energy-efficient
operation and infinitely variable speed control. The wide range is ideal for applications involving high static pressure. This
unit includes an internal microprocessor that can be incorporated into Building Management Systems (BMS) to allow
remote monitoring and control. FFU includes MODBUS® networking control card with closed-loop control capability that
supports air pressure, air flow, and particle count sensors. The motor control panel includes diagnostic indicator lights,
manual speed adjustment, test probe jacks, CAT5e ports, control mode switch and MODBUS® address DIP switch bank.
The EC motor offers high performance, low energy consumption and low noise levels (40 dB) with forward-curved
centrifugal fans. These units comply with Title 24 and ErP 2015 Directive.
The EC motor Control Card can be equipped with a 3/8”-diameter challenge port, which can be used to take differential
pressure measurements to monitor filter performance or insert aerosols for leak-test certification. Port is capped when not
in use.
PRODUCT DIMENSIONS
Nominal Unit
Size (ft.)
Active Filter
Area (sq. ft.) W (in) L (in) H (in) Weight (lbs.)
2’ x 4’ 7.2’ 23.63” 47.56” 12.60” 71
2’ x 4’ (RSR)
5.2’
23.63”
47.63”
14.66”
71
2’ x 3’ 5.3’ 23.63” 35.56” 12.60” 53
2’ x 3’ (RSR)
3.7’
23.63”
35.63”
14.66”
53
2’ x 2’
3.4’
23.63”
23.56”
12.60”
44
2’ x 2’ (RSR) 2.2’ 23.63” 23.63” 14.66” 44
PERFORMANCE DATA
Nominal
Unit Size
(ft.)
Filter Max
CFM
Watts @
Max CFM
Watts @ 90
FPM
Sound (dB.)
@ 90 FPM
2 ’x 4’ HEPA 900 350 180 40
2’ x 4’
HEPA (RSR)
900
350
170
40
2’ x 3’ HEPA 780 325 110 40
2’ x 3’
HEPA (RSR)
780
325
80
40
2’ x 2’
HEPA
475
225
100
40
2’ x 2’ HEPA (RSR) 400 130 70 40

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
3.4.1 120V and 220V Configurations
3.4.1.1 120V Configuration (default)
120V Configuration
1. Black and Red wires are connected to the lower terminal.
2. Yellow Jumper Cable is installed.
3.4.1.2 220V Configuration
220V Configuration
1. Black and Red wires connect to the upper terminal as shown.
2. Yellow Jumper Cable is removed.
Figure 4: Backside view of 120V Configuration
Figure 5: Backside view of 220V Configuration

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
Figure 6: Motor Cable Configurations

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
3.5 EC Motor Control Card
The EC motor control card is a variable-speed controller designed for brushless DC (BLDC), electrically-commutated
(EC) motors. The control card features industry standard MODBUS® networking, precision speed control (1-100%),
and closed-loop control capability. The EC Motor Control panel provides access to LED diagnostics, manual speed
adjustment, test probe jacks, CAT5e ports, the Control Mode DIP Switch, and the MODBUS® Address DIP Switch
Bank.
Figure 7: EC fan filter unit control panel

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
EC Motor Control Card
•Operating Temperature: 0 – 40°C
•Open-frame PCB with standoffs; Panel-mounted
•12-24V DC Power Supply (or network power)
•Two non-directional CAT5e/RJ45 connections for networking
•Motor Tachometer RPM Control
Analog Control Options
•5-10V from controlled voltage source
•4-20mA signal from a sensor or potentiometer
•Internal Closed-Loop Control
•Manual Speed Adjustment
PWM Speed Command Signal
•10V, 80Hz
TACH Motor Speed Input
•10V @ 1mA needed switched to ground
•Maximum 5000 RPM measured
•Minimum 60 RPM measured
Industry Standard MODBUS® Networking
•RTU Protocol
•RS485 9600,8,n,1
3.5.1 Control Modes
The EC Motor Control Card offers three different control modes for operating the FFU: MODBUS® RTU networking,
0-10 VDC analog control, or manual control through an onboard potentiometer.
Manual Control Mode:
The onboard potentiometer can be manually adjusted at the EC Motor Control Panel using a Philips-head
screwdriver. Clockwise rotation increases the motor output, and counterclockwise rotation decreases the motor
output.
Analog Control Mode:
Two terminals located on the EC Motor Control Card are designed to receive either a 0-10 VDC demand signal or 4-
20mA sensor signal to regulate the motor output.
Network Control Mode:
Each EC Motor Control Card in a MODBUS® network must be assigned a unique address set in binary format using
the eight DIP switches in the Address DIP Switch Bank.

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
3.5.2 Test Probe Terminals
The test probe terminals are provided on the EC Motor Control Card to measure the motor RPM or check for a PWM
signal using a multimeter.
Manual or Analog Control Modes:
To measure RPM, set the Address DIP Switches at a value greater than 1. The test probe jacks will output 0-2000
mVDC to represent motor RPM.
Example: 500 mVDC = 500 RPM
To measure demand signal, change the Address DIP Switches to the value of 0.
Note: Changing the address will not interrupt power to the Control Card.
Network Control Mode:
In the MODBUS® network control mode, the test probe terminals will always output 0-2000 mVDC to represent motor
RPM.
Note: Address zero should not be used for Networked Control mode as it is reserved for global commands.
Note: The EC Motor Control Card must be power-cycled for any address changes to take effect.

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
3.5.3 Control Card Electrical Specifications
Electrical Ratings
Input Voltage, AC, 50/60Hz
12 – 28V1AC
Input Voltage, DC
14 – 30V DC
Operating Current, AC
35 mA AC
Operating Current, DC
30 mA DC
Accessory Current 5V, 10V
503mA DC
Accessory Current V.RFU2
1003mA DC
1 Refers to actual AC voltage values
2 V.RFU is rectified and capacitive-filtered, but is unregulated
3 Maximum current values stated in support of a single connected
load
“Stand Alone Operation” Power Source Ratings
Supply Transformer Voltage Rating,
12 – 24V AC
Supply Transformer Power Rating
2 VA
Regulated DC Supply Voltage Rating
14 – 30V DC
Regulated DC Supply Power Rating
2 W
Extended Accessory Output Currents for Stated Input Voltage Condition
Input Voltage Accessory Current, DC mA2
Suggested AC/DC
Source Power
Rating
5V
10V
V.RFU
VA
14V DC Regulated
300
300
500
20,20,30
30V DC Regulated
50
50
500
10,10,60
12V AC1Transformer
100
100
100
5,5,5
28V AC1Transformer
50
50
200
10,10,25
1AC voltage spec refers to actual AC voltage values, i.e., not transformer ratings, etc.
2
Current values stated in support of a single connected load.
Specifications
Horsepower
1/3 HP
Voltage
120/240V, 50/60Hz
Speeds
300 – 1250 RPM
Inputs
2 Way Serial Communication & PWM
Frame
NEMA® 48
Enclosure
Continuous Air Over
Mounting
Belly Band
Amperage
4.2/2.7 Amps

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
Figure 9: Filter-face grille’s metal tabs
4. Cleaning
The HEPA filter installed inside the FFU cannot be cleaned and will typically last for at least a few years depending on several
factors such as ambient conditions, total operating time, fan speed setting (airflow rate), and maintenance of the pre-filters.
When the unit is used in an ISO-classified environment, the HEPA filter will often perform sufficiently for a much longer period of
time. However, if air speed is significantly reduced or the HEPA filter fails to pass certification by an independent certifier, the
HEPA filter may need to be replaced. Be sure to verify the proper operation of all other components in the system before
attempting to replace the HEPA filter. A filter replacement alarm system is available to issue a warning alarm when pressure
reaches twice the initial backpressure; system includes an audible buzzer with silencer that sounds when set point level is
exceeded.
Note: Filter replacement is not time dependent, but performance dependent. The filter should be changed when the fan filter unit can no
longer achieve any of the required conditions such as: particle count, face velocity, room air change rate, and/or room pressure differential.
4.1 Room-Side Filter Replacement (BIBO compatible)
WARNING:
For applications involving risk of exposure to harmful particulates or pathogens in the filter media, use
appropriate PPE and reference your facility’s protocol for safe removal and disposal of filters.
The Room-Side Replaceable (RSR) FFU is designed so that the HEPA or ULPA filter can be replaced from inside the
cleanroom without breaching the controlled environment. The filter assembly is separate from the fan module, which stays
in place in the ceiling grid.
1. First, you must remove the stainless steel screen covering the filter that is held in place with friction catches (See
Figure 8). This screen protects the filter from damage and enhances airflow uniformity.
2. Next, rotate the metal tabs that help hold the HEPA filter in place (See Figure 9).
3. Gently let the used filter drop down, and set aside. The filter assembly is surrounded by a channel containing gel seal.
4. Wipe any residual gel from the knife-edge of the fan module still in the ceiling to prepare for the replacement filter.
5. Position your new filter carefully before pushing into place; the knife-edge of the fan module should be centered in the
channel (equal amounts of gel on both sides). Figure 10 shows the gel-filled channel of the RSR filter.
6. Rotate the metal tabs so that they lock in the new HEPA filter.
7. Reinstall the stainless steel screen by pushing up on the friction catches until the screen clicks into place.
8. To replace the pre-filter located at the top of the fan module, slide the old filter out of the two tracks holding it in place
on top of the FFU and then slide in the new pre-filter.
Figure 8: Friction catches hold the screen to the fan
module housing
Figure 10: Gel-filled channel of RSR filter
WARNING

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
4.2 Top-Side Filter Replacement
Topside replaceable FFUs require the units to be removed from the cleanroom ceiling or hood for filter replacement. This
replacement may require shutting down the cleanroom operation.
1. Disconnect the fan/filter unit from the PDM.
2. Attach double stick tape to a polypropylene panel – place on all four sides. The panel protects the HEPA filter from
damage (See Figure 11).
3. Place the polypropylene panel over the filter screen, making sure that it only adheres to the screen without
overlapping the edges (See Figure 12).
4. Push one side of the FFU up (See Figure 13), rotate it 90° (See Figures 15 and 16) and lower through the ceiling grid.
5. Place the unit on a flat work surface and remove the 10 sheet metal screws that hold the HEPA/ULPA filter to the
case (See Figure 17).
6. Replace with a new HEPA/ULPA filter carefully handling edges only.
7. Secure filter to the case with the same screws used previously.
8. Place unit back onto the ceiling grid.
Figure 11: Polypropylene panel with tape
Figure 12: Panel attaching to exposed HEPA filter
Figure 13: Panel fully attached to filter screen without
overlapping edges
Figure 14: FFU pushed up on one side for removal

Terra Universal Product Manual
WhisperFlow® Fan Filter Units
© Copyright 2021 Terra Universal Inc. All rights reserved.
Terra Universal, Inc. • TerraUniversal.com • 800 S. Raymond Ave. • Fullerton, CA 92831 • TEL: [phone] • FAX: [phone]
Figure 17: Diagram of FFU assembly
Figure 15: Personnel rotating FFU to remove from ceiling
grid
Figure 16: FFU rotated 90° and lowered completely
from ceiling grid