TSI Instruments SUREFLOW 8635-M Operation And Service Manual

SUREFLOW™

ROOM PRESSURE MONITOR

MODELS 8635-M

OPERATION AND SERVICE MANUAL

P/N 1980272, REVISION E

FEBRUARY 2013

SUREFLOW™

ROOM PRESSURE MONITOR

MODELS 8635-M

OPERATION AND SERVICE MANUAL

P/N 1980272, REVISION E

FEBRUARY 2013

U.S. AND CANADA OTHER COUNTRIES

Sales & Customer Service: Sales & Customer Service:
[phone]/[phone] (001 651) 490-2811
Fax: Fax:
[phone] (001 651) 490-3824

SHIP/MAIL TO: E-MAIL

TSI Incorporated [e-mail]
ATTN: Customer Service
500 Cardigan Road WEB SITE
Shoreview, MN 55126 www.tsi.com
USA

Copyright  TSI Incorporated / 2000-2013 / All rights reserved.
Part number 1980272, Revision E
LIMITATION OF WARRANTY AND LIABILITY (effective June 2011)

Seller warrants the goods sold hereunder, under normal use and service as described in the operator's
manual, shall be free from defects in workmanship and material for 24 months, or if less, the length of
time specified in the operator's manual, from the date of shipment to the customer. This warranty
period is inclusive of any statutory warranty. This limited warranty is subject to the following exclusions
and exceptions:

a. Hot-wire or hot-film sensors used with research anemometers, and certain other components when

indicated in specifications, are warranted for 90 days from the date of shipment;
b. Pumps are warranted for hours of operation as set forth in product or operator’s manuals;
c. Parts repaired or replaced as a result of repair services are warranted to be free from defects in

workmanship and material, under normal use, for 90 days from the date of shipment;
d. Seller does not provide any warranty on finished goods manufactured by others or on any fuses,

batteries or other consumable materials. Only the original manufacturer's warranty applies;
e. Unless specifically authorized in a separate writing by Seller, Seller makes no warranty with respect

to, and shall have no liability in connection with, goods which are incorporated into other products or

equipment, or which are modified by any person other than Seller.
The foregoing is IN LIEU OF all other warranties and is subject to the LIMITATIONS stated herein. NO

OTHER EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR PARTICULAR PURPOSE OR
MERCHANTABILITY IS MADE. WITH RESPECT TO SELLER’S BREACH OF THE IMPLIED
WARRANTY AGAINST INFRINGEMENT, SAID WARRANTY IS LIMITED TO CLAIMS OF DIRECT
INFRINGEMENT AND EXCLUDES CLAIMS OF CONTRIBUTORY OR INDUCED
INFRINGEMENTS. BUYER’S EXCLUSIVE REMEDY SHALL BE THE RETURN OF THE

PURCHASE PRICE DISCOUNTED FOR REASONABLE WEAR AND TEAR OR AT SELLER’S

OPTION REPLACEMENT OF THE GOODS WITH NON-INFRINGING GOODS.

TO THE EXTENT PERMITTED BY LAW, THE EXCLUSIVE REMEDY OF THE USER OR BUYER,
AND THE LIMIT OF SELLER'S LIABILITY FOR ANY AND ALL LOSSES, INJURIES, OR DAMAGES
CONCERNING THE GOODS (INCLUDING CLAIMS BASED ON CONTRACT, NEGLIGENCE, TORT,
STRICT LIABILITY OR OTHERWISE) SHALL BE THE RETURN OF GOODS TO SELLER AND THE
REFUND OF THE PURCHASE PRICE, OR, AT THE OPTION OF SELLER, THE REPAIR OR
REPLACEMENT OF THE GOODS. IN THE CASE OF SOFTWARE, SELLER WILL REPAIR OR
REPLACE DEFECTIVE SOFTWARE OR IF UNABLE TO DO SO, WILL REFUND THE PURCHASE
PRICE OF THE SOFTWARE. IN NO EVENT SHALL SELLER BE LIABLE FOR LOST PROFITS OR
ANY SPECIAL, CONSEQUENTIAL OR INCIDENTAL DAMAGES. SELLER SHALL NOT BE
RESPONSIBLE FOR INSTALLATION, DISMANTLING OR REINSTALLATION COSTS OR
CHARGES. No Action, regardless of form, may be brought against Seller more than 12 months after a
cause of action has accrued. The goods returned under warranty to Seller's factory shall be at Buyer's
risk of loss, and will be returned, if at all, at Seller's risk of loss.

Buyer and all users are deemed to have accepted this LIMITATION OF WARRANTY AND LIABILITY,
which contains the complete and exclusive limited warranty of Seller. This LIMITATION OF
WARRANTY AND LIABILITY may not be amended, modified or its terms waived, except by writing
signed by an Officer of Seller.

SERVICE POLICY

Knowing that inoperative or defective instruments are as detrimental to TSI as they are to our
customers, our service policy is designed to give prompt attention to any problems. If any
malfunction is discovered, please contact your nearest sales office or representative, or call TSI's
Customer Service department at [phone].

TRADEMARKS

TSI and TSI logo are registered trademarks of TSI Incorporated.
SureFlow is a trademark of TSI Incorporated.

ii

CONTENTS

HOW TO USE THIS MANUAL ........................................................................................... 1

PART ONE USER BASICS ........................................................................... 1

The Instrument ............................................................................. 1

Operator Panel ............................................................................. 3

Alarms .......................................................................................... 5

Before Calling TSI ........................................................................ 6

PART TWO TECHNICAL SECTION .............................................................. 7

Software Programming ................................................................ 8

Menu and Menu Items ............................................................... 12

Calibration .................................................................................. 25

Maintenance and Repair Parts .................................................. 28

Troubleshooting Section ............................................................ 29

APPENDIX A SPECIFICATIONS .................................................................... 37

APPENDIX B WIRING INFORMATION .......................................................... 39

APPENDIX C ACCESS CODES ..................................................................... 41

How to Use This Manual

The SureFlow monitor Operation and Service Manual is divided into two parts. Part one
describes how the SureFlow unit functions and how to interface with the device. This
section should be read by users, facilities staff, and anyone who requires a basic
understanding of how the SureFlow monitor operates.

Part two describes the technical aspects of the product which includes operation,
calibration, configuration, maintenance, and troubleshooting. Part two should be read by
personnel programming or maintaining the unit. TSI recommends thoroughly reading this
manual before changing any software items.

NOTE: This operation and service manual assumes proper SureFlow monitor

installation. Refer to the Installation Instructions to determine if the SureFlow
monitor has been properly installed.

iii

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iv

PART ONE

User Basics

Reading product manuals should not be a difficult and time consuming process. This
section provides a brief but thorough overview of the SureFlow product by maximizing
information with minimal reading. These few pages explain the purpose (The Instrument),
and the operation (Useful User Information, Digital Interface Module, Alarms) of the unit.
Technical product information is available in Part Two of the manual. The manual
focuses on laboratory spaces, but the product information is accurate for any room
pressure application.

The Instrument

SureFlow monitor measures and reports “room pressure.” Proper room pressure can
control airborne contaminants that can adversely affect experiments, workers in the
laboratory, and people in the laboratory vicinity. For example, laboratories with fume
hoods need negative room pressure (air flowing into the room), to minimize exposure to
people outside the laboratory. The fume hood is the first level of containment, and the
laboratory itself is the second level of containment.

Room pressure, or pressure differential, is created when one space (hallway) is at a
different pressure than an adjoining space (laboratory). When a pressure differential is
created between two spaces, air is forced to flow from the higher pressure space to the
lower pressure space. The direction of air flow is one component of proper room
pressure. The second component of room pressure is the speed or how fast is the air
moving between the two spaces. The SureFlow monitor provides both pieces of
information by measuring whether the air is flowing into or out of a laboratory, and the
speed of the air.

Negative room pressure is present when air flows from a hallway into the laboratory. If air
flows from the laboratory into the hallway the room is under positive pressure. Figure 1
gives a graphic example of positive and negative room pressure.

An example of negative pressure is a bathroom with an exhaust fan. When the fan is
turned on, air is exhausted out of the bathroom creating a slight negative pressure when

Figure 1: Room Pressure

1

compared to the hallway. This pressure differential forces air to flow from the hallway into
the bathroom.

The SureFlow device informs the laboratory users when the laboratory is under proper
pressure, and provides alarms when the room pressure is inadequate. If the room
pressure is in the safe range, a green light is on. If the pressure is inadequate, a red
alarm light and audible alarm turn on.

The SureFlow monitor consists of two pieces: a pressure sensor and a Digital Interface
Module (DIM). The pressure sensor is mounted above the doorway entrance to the
laboratory. Usually the DIM is mounted close to the entrance to the laboratory. The
pressure sensor continuously measures the room pressure and provides room pressure
information to the DIM. The DIM continuously reports the room pressure and activates
the alarms when necessary. SureFlow monitor is a continuous measuring system
providing instant information on the room pressure.

Useful User Information

The DIM has a green light and red light to indicate room pressure status. The green light
is on when the room has proper room pressure. The red light comes on when an alarm
condition exists.

Sliding the door panel to the right reveals a digital display and keypad (Figure 2). The
display shows detailed information about room pressure, alarms, etc. The keypad allows
the user to test the device, and program or change the device parameters.

Figure 2: Digital Interface Module (DIM)

SureFlow monitor has two levels of user information:

1. SureFlow monitor has a red light and green light to provide continuous
information on room pressure status.

2. SureFlow monitor has a hidden operator panel providing detailed room
status information, self-testing capabilities, and access to the software
programming functions.

NOTE: The unit provides continuous room pressure status through the red and green

light. The operator panel is normally closed unless further information on room
pressure status is needed, or software programming is required.

2 Part One

Operator Panel

The DIM in Figure 3 shows the location of the digital display, keypad and lights. An
explanation of the operator panel follows the figure.

Figure 3: SureFlow Monitor Operator Panel - Open

Green / Red light

The green light is on when all the conditions for proper room pressure are adequate. This
light indicates the laboratory is operating safely. If any of the room pressure conditions
cannot be satisfied the green light turns off, and the red alarm light turns on.

Operator Panel

A cover hides the operator panel. Sliding the door panel to the right exposes the operator
panel (Figure 2).

Digital Display

The alphanumeric digital display is a two line display that indicates actual room pressure
(positive or negative), alarm status, menu options, and error messages. In normal
operation (green light is on), the display continuously scrolls information about room
pressure, and other variables programmed; flow, air changes per hour, etc.. The
variables that scroll depend on the options installed.

As an example, if an alarm condition occurs the variable that normally scrolls
STANDARD STANDARD
NORMAL will change to read ALARM = *

* will state type of alarm; low pressure, high pressure, flow
NOTE: When switch input (pins 11 & 12) is closed, the word standard is replaced with

remote on display.
When programming the unit, the display will change and now show menus, menu items,

and current value of the item, depending on the specific programming function being
performed.

Keypad

The keypad has six keys. The gray keys with black letters are user information keys. In
normal operation these keys are active. The gray keys with blue characters are used to
program the unit. The red emergency key has no function on the monitor and has been
disconnected. A thorough description of each key is given below.

User Basics 3

User Keys - Gray with Black Letters

The four keys with black letters provide the user information without changing the
operation or the function of the unit.

TEST Key

The TEST key initiates an instrument self-test. Pressing the TEST key activates
a scrolling sequence on the display that shows the product model number,
software version, and all set point and alarm values. The unit then performs a
self test that tests the display, indicator lights, audible alarm, and internal
electronics to ensure they are operating properly. If a problem with the unit
exists, DATA ERROR will be displayed. The user should have qualified personal
determine the problem with the unit.

RESET Key

The RESET key performs two functions. 1) Resets the alarm light, alarm
contacts, and audible alarm when in a latched or non automatic reset mode. The
room pressure must be in the safe or normal range before the RESET key will
operate. 2) Clears any displayed error messages.

MUTE Key

The MUTE key temporarily silences the audible alarm. The time the alarm is
temporarily silenced is programmable by the user (see MUTE TIMEOUT). When
the mute period ends, the audible alarm turns back on if the alarm condition is
still present.

NOTE: The user can program the audible alarm to be permanently turned off

(see AUDIBLE ALM).

AUX Key

The AUX key is active only in specialty applications and is not used on the
standard SureFlow monitor. If the AUX key is used, a separate manual
supplement will explain the AUX key function.

Programming Keys - Gray with Blue Characters

The four keys with blue print are used to program or configure the unit to fit a particular
application.

WARNING: Pressing these keys will change how the unit functions, so please

thoroughly review the manual before changing menu items.

MENU Key

The MENU key performs three functions. 1) Provides access to the menus when
in the normal operating mode. 2) When the unit is being programmed, the MENU
key acts as an escape key to remove you from an item or menu, without saving
data. 3) Returns the unit to the normal operating mode. The MENU key is further
described in the Software Programming section of this manual.

SELECT Key

The SELECT key performs three functions. 1) Provides access to specific
menus. 2) Provides access to menu items. 3) Saves data. Pressing the key when
finished with a menu item will save the data, and exit you out of the menu item.

4 Part One

/ Keys

The / keys are used to scroll through the menus, menu items, and through
the range of item values that can be selected. Depending on the item type the
values may be numerical, specific properties (on / off), or a bar graph.

Alarms

SureFlow monitor has visual (red light) and audible alarms to inform the user of changing
conditions. The alarm levels (set points) are determined by administrative personnel,
Industrial Hygienists, or the facilities group depending on the organization.

The alarms, audible and visual, will activate whenever the preset alarm level is reached.
Depending on the SureFlow monitor items installed, programmed alarms will activate
when room pressure is low or inadequate, when room pressure is high or too great, or
when the supply or exhaust air flow is insufficient. When the laboratory is operating
safely, no alarms will sound.

Example: The low alarm is preset to activate when the room pressure reaches -0.001

inches H2O. When the room pressure drops below -0.001 inches H2O (gets
closer to zero), the audible and visual alarms activate. The alarms turn off
(when set to unlatched) when the unit returns to the safe range which is
defined as negative pressure greater than -0.001 inches H2O.

Visual Alarm Operation

The red light on the front of the unit indicates an alarm condition. The red light is on for all
low and high alarm conditions.

Audible Alarms

The audible alarm is continuously on in all low and high alarm conditions. The audible
alarm can be temporarily silenced by pressing the MUTE key. The alarm will be silent for
a period of time (see MUTE TIMEOUT to program time period). When the time out period
ends, the audible alarm turns back on if the alarm condition is still present.

The user can program the audible alarm to be permanently turned off (see AUDIBLE

ALM). The red alarm light will still turn on in alarm conditions when audible alarm is

turned off.
The audible and visual alarms can be programmed to either automatically turn off when

the unit returns to the safe range or to stay in alarm until the RESET key is pressed (See

ALARM RESET).

User Basics 5

Before Calling TSI

This manual should answer most questions and resolve most problems the user may
encounter. If you need assistance or further explanation, contact your local TSI
representative or TSI. TSI is committed to providing high quality products backed by
outstanding service.

Please have the following information available prior to contacting your authorized TSI
Manufacturer's Representative or TSI:

- Model number of unit* 8635-M- ____

- Software revision level*

- Facility where unit is installed
* First two items that scroll when TEST key is pressed
Due to the different SureFlow models available, the above information is needed to

accurately answer your questions.
For the name of your local TSI representative or to talk to TSI service personnel, please

call TSI at:

U.S. AND CANADA OTHER COUNTRIES

Sales & Customer Service: Sales & Customer Service:
[phone]/[phone] (001 651) 490-2811
Fax: Fax:
[phone] (001 651) 490-3824

SHIP/MAIL TO: E-MAIL

TSI Incorporated [e-mail]
ATTN: Customer Service
500 Cardigan Road WEB SITE
Shoreview, MN 55126 www.tsi.com
USA

6 Part One

PART TWO

Technical Section

The SureFlow monitor is ready to use after being properly installed. The pressure sensor
is factory calibrated prior to shipping, and should not need adjustment. The Digital
Interface Module (DIM) is programmed with a default configuration that can be easily
modified to fit your application.

The Technical section is separated into five parts that cover all aspects of the unit. Each
section is written as independently as possible to minimize flipping back and forth
through the manual for an answer.

The Software Programming section explains the programming keys on the DIM. In
addition, the programming sequence is described, which is the same regardless of the
menu item being changed. At the end of this section is an example of how to program the
DIM.

The Menu and Menu Item section lists all of the software items available to program and
change. The items are grouped by menu which means all calibration items are in one
menu, alarm items in another, etc. The menu items and all related information is listed in
table format and includes programming name, description of menu of item, range of
programmable values, and how the unit shipped from the factory (default values).

The Calibration section describes the required technique to compare the pressure sensor
reading to a thermal anemometer, and how to adjust the zero and span to obtain an
accurate calibration. This section also describes how to zero a flow station.

The Maintenance and Repair Parts section covers all routine maintenance of equipment,
along with a list of repair parts.

The Troubleshooting section is split into two areas: Mechanical operation of the unit and
system performance. Many external variables will affect how the unit functions so it is
critical to first determine if the unit is having mechanical problems - i.e., no display on
unit, remote alarms don’t function, etc. If problems still exist, look for performance
problems (i.e., doesn’t seem to read correctly, display fluctuates, etc.). The first step is to
determine that the system is mechanically operating correctly, followed by modifying the
configuration to eliminate the performance problems.

7

Software Programming

Programming the SureFlow monitor is quick and easy if the programming keys are
understood, and the proper keystroke procedure is followed. The programming keys are
defined first, followed by the required keystroke procedure. At the end of this section is a
programming example.

NOTE: The unit is always operating while programming. When a menu item value is

changed, the new value takes effect immediately after saving the change.

NOTE: This section covers programming the instrument through the keypad and display.

If programming through RS-485 communications, use the host computer’s
procedure. The changes take place immediately upon saving data in the
instrument.

Programming Keys

The four keys with blue characters (refer to Figure 4) are used to program or configure
the unit to fit your particular application. Programming the instrument will change how the
unit functions, so thoroughly review the items to be changed.

Figure 4. Programming Keys

MENU Key

The MENU key has three functions.

1. The MENU key is used to gain access to the menus when the unit is in the
normal operating mode. Pressing the key once will exit the normal operating
mode and enter the programming mode. When the MENU key is first pressed,
the first two menus are listed.

2. When the unit is being programmed, the MENU key acts like an escape key.
 When scrolling through the main menu, pressing the MENU key will return

the unit to standard operating mode.

 When scrolling through the items on a menu, pressing the MENU key will

return you to the list of menus.

 When changing data in a menu item, pressing the MENU key will escape out

of the item without saving changes.

3. When programming is complete, pressing the MENU key will return the unit to
normal operating mode.

8 Part Two

SELECT Key

The SELECT key has three functions.

1. The SELECT key is used to gain access to specific menus. To access a menu,
scroll through the menus (using arrow keys) and place the flashing cursor on the
desired menu. Press the SELECT key to select the menu. The first line on the
display will now be the selected menu, and the second line will show the first
menu item.

2. The SELECT key is used to gain access to specific menu items. To access a
menu item scroll through the menu items until item appears. Press the SELECT
key and the menu item will now appear on the first line of the display and the
second line will show the item value.

3. Pressing the SELECT key when finished changing an item will save the data and
exit back to the menu items. An audible tone (3 beeps) and visual display
(“saving data”) gives confirmation data is being saved.

/ Keys

The / keys are used to scroll through the menus, menu items, and through
the range of item values that can be selected. Depending on the menu item
selected the value may be numerical, specific property (on / off), or a bar graph.

NOTE: When programming a menu item, continuously pressing the arrow key

will scroll through the values faster than if arrow key is pressed and
released.

Keystroke Procedure

The keystroke operation is consistent for all menus. The sequence of keystrokes to
follow is the same regardless of the menu item being changed.

1. Press the MENU key to access the main menu.

2. Use the / keys to scroll through the menu choices. The blinking cursor needs
to be on the first letter of the menu you want to access.

3. Press the SELECT key to access chosen menu.

4. The menu selected is now displayed on line one and the first menu item is
displayed on line 2. Use the / keys to scroll through the menu items. Scroll
through the menu items until desired item is displayed.

NOTE: If “Enter Code” is flashing, the access code must be entered before you

can enter the menu. Access codes are found in Appendix C. Appendix C
may have been removed from the manual for security reasons.

5. Press the SELECT key to access chosen item. The top line of display shows
menu item selected, while the second line shows current item value.

6. Use the / keys to change item value.

7. Save the new value by pressing the SELECT key (pressing the MENU key will
exit out of menu function without saving data).

8. Press the MENU key to exit current menu, and return to main menu.

9. Press the MENU key again to return to normal instrument operation.

Technical Section 9

 Unit is in normal operation scrolling

room pressure, flows, etc. Pressure is
shown in this case:

PRESSURE

-.00085 “H2O

 Press the MENU key to gain access to

the menus.

MENU

The first 2 menu choices

are displayed.

ALARM
CONFIGURE

 Press the SELECT key to access the

ALARM menu.

NOTE: Blinking cursor must be on A in

Alarm.

SELECT

Line 1 shows menu selected.
Line 2 shows first menu item.

ALARM
LOW ALARM

 Press the  key until HIGH ALARM is shown

on display.



Menu selected

Item name

ALARM
HIGH ALARM

 Press the SELECT key to access the

high alarm set point. The item name
(HIGH ALARM) will now be displayed
on line 1, and the item's current value
will be displayed on line 2.

SELECT

Item Name

Current Value

HIGH ALARM

-.00200 "H2O

 Press the  key to change the high

alarm set point to - 0.003 inches H2O.



HIGH ALARM

- .00300 "H2O

 Press the SELECT key to save the new

high alarm set point.

SELECT

If more than one item is to be changed, skip steps 8 and 9 until all changes are complete.
If more items in the same menu are to be changed, scroll to them after saving the data
(step 7). If other menus need to be accessed, press the MENU key once to access list of
menus. The instrument is now at step 2 of the keystroke sequence.

Programming Example

The following example demonstrates the keystroke sequence explained above. In this
example the high alarm set point will be changed from -0.002 inches H2O to -0.003
inches H2O.

10 Part Two

Three short beeps will sound

indicating that the data is being
saved.

HIGH ALARM
Saving Data

Immediately after the data is saved,

the SureFlow monitor will return to
the menu level displaying the menu
title on the top line of the display and
the menu item on the bottom line
(goes to step 3).

ALARM
HIGH ALARM

 Press the MENU key once to return to

the menu level:

MENU

ALARM
CONFIGURE

 Press the MENU key a second time to

return to the normal operating level:

MENU

Unit is now back in normal

operation

PRESSURE

-.00085 "H2O

WARNING: If the MENU key was pressed instead of the SELECT

key, the new data would not have been saved, and the
SureFlow monitor would have escaped back to the menu
level shown in step 3.

Technical Section 11

Menu and Menu Items

The SureFlow monitor is a very versatile device which can be configured to meet your
specific application. This section describes all of the menu items available to program
and change (except diagnostics menu). Changing any item is accomplished by using the
keypad, or if communications are installed through the RS-485 Communications port. If
you are unfamiliar with the keystroke procedure please see Software Programming for a
detailed explanation. This section provides the following information:

 Complete list of menu and all menu items.
 Gives the menu or programming name.
 Defines each menu item’s function; what it does, how it does it, etc.
 Gives the range of values that can be programmed.
 Gives default item value (how it shipped from factory).

The menus covered in this section are divided into groups of related items to ease
programming. As an example all calibration items are in one menu, alarm information in
another, etc. The manual follows the menus as programmed in the controller. The menu
items are always grouped by menu and then listed in menu item order, not alphabetical
order. Figure 5 shows a chart of all the Model 8635-M monitor menu items.

12 Part Two

ALARM
LOW ALARM

HIGH ALARM
REM LOW ALM
REM HIGH ALM
MIN FLOW ALM
ALARM RESET
AUDIBLE ALM
ALARM DELAY
DOOR DELAY
MUTE TIMEOUT
ACCESS CODE

CONFIGURE

DISPLAY AVG
UNITS
DUCT AREA
FLO STA TYPE
TOP VELOCITY
ROOM VOLUME
ACCESS CODE

CALIBRATION
SENSOR ZERO

SENSOR SPAN
FLOW ZERO
ELEVATION
ACCESS CODE

INTERFACE
NET PROTOCOL

NET ADDRESS
OUTPUT RANGE
OUTPUT SIG
ACCESS CODE

DIAGNOSTICS *
SENSOR INPUT

SENSOR STAT
ANALOG OUT
SWITCH INPUT
FLOW INPUT
LOW ALM REL
HIGH ALM REL
ACCESS CODE

* Menu item description located in Troubleshooting section

Figure 5: Menu Items - Model 8635-M Monitor

Technical Section 13

14 Part Two

ALARM MENU

MENU ITEM

SOFTWARE

NAME

ITEM DESCRIPTION

ITEM RANGE

DEFAULT

VALUE

LOW
PRESSURE
ALARM

LOW ALARM

The LOW ALARM item sets the low pressure alarm set point. A
low alarm condition is defined as when the magnitude of the
room pressure falls below or goes in the opposite direction of
the LOW ALARM set point.

This item is enabled when the SWITCH INPUT contact closure,
pins 11 and 12, is open, or the RS 485 communications sends
a command.

OFF, 0 to -0.19500

"H2O

0 to +0.19500 "H2O

OFF
HIGH
PRESSURE
ALARM

HIGH
ALARM

The HIGH ALARM item sets the high pressure alarm set point.
A high alarm condition is defined as when the magnitude of the
room pressure rises above the HIGH ALARM set point.

This item is enabled when the SWITCH INPUT contact closure,
pins 11 and 12, is open, or the RS 485 communications sends
a command.

OFF, 0 to -0.19500

"H2O

0 to +0.19500 "H2O

OFF

REMOTE OR
SECOND LOW
ALARM

REM LOW
ALM

The REM LOW ALM item sets a remote or second low pressure
alarm set point. A remote low alarm condition is defined as
when the magnitude of the room pressure falls below or goes in
the opposite direction of the REM LOW ALM set point.

This item is enabled when the SWITCH INPUT contact closure,
pins 11 and 12, is closed, or the RS 485 communications sends
a command.

OFF, 0 to -0.19500

"H2O

0 to +0.19500 "H2O

OFF

REMOTE OR
SECOND
HIGH ALARM

REM HIGH
ALM

The REM HIGH ALM item sets a remote or second high
pressure alarm set point. A high alarm condition is defined as
when the magnitude of the room pressure rises above the REM
HIGH ALM set point.

This item is enabled when the SWITCH INPUT contact closure,
pins 11 and 12, is closed, or the RS 485 communications sends
a command.

OFF, 0 to -0.19500

"H2O

0 to +0.19500 "H2O

OFF

Technical Section 15

ALARM MENU

MENU ITEM

SOFTWARE

NAME

ITEM DESCRIPTION

ITEM RANGE

DEFAULT

VALUE

MINIMUM
FLOW ALARM

MIN FLOW
ALM

The MIN FLOW ALM item sets the duct’s flow alarm set point. A
minimum flow alarm is defined as when the duct flow is less
than the MIN FLOW ALM set point. Flow station can be
mounted in either the supply or exhaust duct. (Flow station is
optional).

NOTE: The DUCT AREA (configure menu) must be entered

before a MIN FLOW ALM can be programmed.

OFF

Pressure based flow

stations; 0 to

2832 ft/MIN times the

duct area in square

feet (ft2)
Linear based flow
stations 0 to TOP

VELOCITY times the

duct are in square

feet (ft2)

OFF

ALARM
RESET

ALARM
RESET

The ALARM RESET item selects how the alarms terminate
after the unit returns to the safe pressure range (pressure or
flow). UNLATCHED (alarm follow) automatically resets the
alarms when the unit reaches the safe pressure range.
LATCHED requires the staff to press the RESET key after the
unit returns to the safe pressure range. The ALARM RESET
affects the audible alarm, visual alarm, and relay output, which
means all are latched or unlatched.

LATCHED

OR

UNLATCHED

UNLATCHE

D

AUDIBLE
ALARM

AUDIBLE
ALM

The AUDIBLE ALM item selects whether the audible alarm is
turned ON or OFF. Selecting ON requires the staff to press the
MUTE key to silence the audible alarm. Selecting OFF
permanently mutes all audible alarms.

ON or OFF

ON

ALARM DELAY

ALARM
DELAY

The ALARM DELAY determines the length of time the alarm is
delayed after an alarm condition has been detected. This delay
affects the visual alarm, audible alarm, and relay outputs. An
ALARM DELAY prevents nuisance alarms from people entering
and leaving the laboratory.

The ALARM DELAY is enabled when the SWITCH INPUT
contact closure, pins 11 and 12, is open, or the RS 485
communications sends a command.

20 to 600 SECONDS

20

SECONDS

16 Part Two

ALARM MENU

MENU ITEM

SOFTWARE

NAME

ITEM DESCRIPTION

ITEM RANGE

DEFAULT

VALUE

DOOR DELAY

DOOR
DELAY

The DOOR DELAY item is an alarm delay used when the door
will be open for an extended period of time. The DOOR DELAY
is usually set for a longer period of time than the ALARM
DELAY. This delay affects the visual alarm, audible alarm, and
relay outputs. The DOOR DELAY prevents nuisance alarms
from people leaving the doors open to move equipment into or
out of the laboratory, or when a large group will be entering or
leaving the laboratory.

This DOOR DELAY is enabled when the SWITCH INPUT
contact closure, pins 11 and 12, is closed, or the RS 485
communications sends a command.

NOTE: When the switch input is closed, the remote alarms are

activated, and the standard alarms and ALARM DELAY
are turned off. Set the remote alarms equal to the
standard alarms if the same alarms are required (delay
would just change).

20 to 600 SECONDS

20

SECONDS

MUTE
TIMEOUT

MUTE
TIMEOUT

The MUTE TIMEOUT determines the length of time the audible
alarm is silenced after the MUTE key is pressed. This delay
temporarily mutes the audible alarm.

NOTE: If the DIM is in alarm when MUTE TIMEOUT expires,

the audible alarm turns on. When the pressure returns
to the safe range, the MUTE TIMEOUT is canceled. If
the room goes back into an alarm condition, the MUTE
key must be pressed again to mute the audible alarm.

5 to 30 MINUTES

5 MINUTES

ACCESS
CODE

ACCESS
CODE

The ACCESS CODE item selects whether an access code
(pass code) is required to enter the menu. The ACCESS CODE
item prevents unauthorized access to a menu. If the ACCESS
CODE is ON a code is required before the menu can be
entered. Conversely if the ACCESS CODE is OFF no code is
required to enter the menu.

ON or OFF

OFF

Technical Section 17

ALARM MENU

MENU ITEM

SOFTWARE

NAME

ITEM DESCRIPTION

ITEM RANGE

DEFAULT

VALUE

END OF
MENU

The END OF MENU item informs the user that the end of a
menu has been reached. The user can either scroll back up the
menu to make changes, or press the SELECT or MENU key to
exit out of the menu.

ALARM CONSTRAINTS

There are a number of constraints built into the software that prevent users from programming conflicting alarm information. These are as
follows:

1. Remote alarms. The remote alarms are only active when the switch input (pins 11 and 12) is closed. When the remote
alarms are active, the standard alarms are turned off.

2. The SureFlow monitor is programmed not to allow the pressure alarms to be programmed within 40 ft/min (+0.00028 “
H

2

O at 0.001 “H

2

O) of each other.

Example: The LOW ALARM set point is -0.00072 “H2O. The HIGH ALARM set point cannot be set lower than

-0.00128 “H2O.

3. The alarms, both standard and remote, can be programmed for positive or negative pressure. However, both the low and
high alarm must be set either positive or negative. The DIM does not allow one positive alarm and one negative alarm.

4. Alarms do not terminate until the pressure exceeds the alarm set point. The alarm set point must be slightly exceeded
before alarm will terminate.

5. The ALARM RESET item selects how the alarms will terminate when monitor returns to the safe range. The pressure and
flow alarms all terminate the same; they are either latched or unlatched. If unlatched is selected the alarms automatically
turn off when the value slightly exceeds the alarm set point. If latched is selected the alarms will not terminate until the
pressure exceeds the alarm set point and the RESET key is pressed.

6. There is a programmable ALARM DELAY (and optional DOOR DELAY) that determines how long to delay before
activating the alarms. This delay affects all pressure and flow alarms. The door delay is active when switch input (pins 11
and 12) is closed.

7. The MUTE TIMEOUT item temporarily turns the audible alarm off for all pressure and flow alarms.

18 Part Two

ALARM CONSTRAINTS (continued)

8. The display can only show one alarm message. Therefore, the controller has an alarm priority system, with the highest
priority alarm being displayed. If multiple alarms exist, the lower priority alarms will not display until after the highest
priority alarm has been eliminated. The alarm priority is as follows:

Pressure sensor - low alarm
Pressure sensor - high alarm
Flow station - minimum flow
Data error

9. The low and high alarms are absolute values. The chart below shows how the values must be programmed in order to
operate correctly.

-0.2 inches H2O 0 +0.2 inches H2O
(maximum negative) (maximum positive)

High Low Zero Low High
Negative Negative Positive Positive
Alarm Alarm Alarm Alarm

The value of each set point or alarm is unimportant (except for small dead band) in graph above. It is important to
understand that the negative (positive) low alarm must be between zero (0) pressure and the negative (positive) high
alarm value.

Technical Section 19

CONFIGURE MENU

MENU ITEM

SOFTWARE NAME

ITEM DESCRIPTION

ITEM RANGE

DEFAULT

VALUE

DISPLAY
AVERAGE

DISPLAY AVG

The DISPLAY AVG item selects the display’s averaging

period. The display averaging period is the length of time the
room pressure has been averaged before being displayed.
The DISPLAY AVG item value may be set between 0.75 and
40 seconds. The higher the averaging value, the more stable
the display.

0.75, 1, 2, 3, 5,
10, 20 or 40

seconds

20 seconds

UNITS

UNITS

The UNITS item selects the unit of measure that the monitor
displays all values (except calibration span). These units
display for all menu items alarm set points, flows, etc.

FT/MIN, m/s,

"H2O

Pa, mm H2O

"H2O

DUCT AREA

DUCT AREA

The DUCT AREA item is used to input the duct size. The
duct size is needed to compute the flow out of the room. This
item requires a TSI flow station to be mounted in the duct.

When a duct area if programmed, the display will
automatically scroll the actual flow as part of the display
sequence. If a zero value is entered, the flow value will not
scroll on the display.

If the DIM displays English units, area must be entered in
square feet. If metric units are displayed area must be
entered in square meters.

0 to 10 square

feet

(0 to 0.9500

square meters)

The DIM does

not compute

area. The area

must be first

calculated and

then entered into

the unit.

0

FLOW
STATION
TYPE

FLO STA TYPE

The FLO STA TYPE item is used to select the input signal for
the flow station. PRESSURE is selected when TSI flow
stations with pressure transducers are installed. LINEAR is
selected when a linear output flow station is installed (0-5
VDC): Typically a thermal anemometer based flow station.

PRESSURE or

LINEAR

PRESSURE

MAXIMUM
FLOW
STATION
VELOCITY

TOP
VELOCITY

The TOP VELOCITY item is used to input the maximum
velocity of a linear flow station. A TOP VELOCITY must be
input for linear flow station to operate.

NOTE: Pressure based flow stations must set this function
to zero.

0 to 5,000

FT/MIN

0

20 Part Two

CONFIGURE MENU

MENU ITEM

SOFTWARE NAME

ITEM DESCRIPTION

ITEM RANGE

DEFAULT

VALUE

ROOM
VOLUME

ROOM VOLUME

The ROOM VOLUME item is used to input the volume of the
room. The room volume is required to calculate air changes
per hour.

Entering a value for the volume will add the air changes per
hour value to the display’s scrolling sequence. If a zero value
is entered the air changes per hour will not scroll on the
display.

If the DIM displays English units, area must be entered in cubic
feet. If metric units are displayed area must be entered in cubic
meters.

The air change per hour is calculated using the ROOM
VOLUME and the input from the air flow station. If no flow
station is installed, a zero value should be entered.

0 to 20,000 cubic

feet

(0 to 550 cubic

meters)

The DIM does

not compute
volume. The

volume must be

first calculated

and then entered

into the unit.

0

ACCESS
CODE

ACCESS CODE

The ACCESS CODE item selects whether an access code
(pass code) is required to enter the menu. The ACCESS
CODE item prevents unauthorized access to a menu. If the
ACCESS CODE is

ON or OFF

OFF

ON a code is required before the menu can be entered.
Conversely if the ACCESS CODE is OFF no code is
required to enter the menu.

END OF MENU

The END OF MENU item informs the user that the end of a
menu has been reached. The user can either scroll back up
the menu to make changes, or press the SELECT or MENU
key to exit out of the menu.

Technical Section 21

CALIBRATION MENU

MENU ITEM

SOFTWARE

NAME

ITEM DESCRIPTION

ITEM RANGE

DEFAULT

VALUE

SENSOR

ZERO

SENSOR

ZERO

The SENSOR ZERO item is used to calibrate the SureFlow
pressure sensor.

A sensor zero should be established prior to adjusting the
sensor span (see Calibration section following menu item
section).

NONE

Unit is
factory
calibrated.
No initial
adjustment
should be
necessary.

SENSOR
SPAN

SENSOR
SPAN

The SENSOR SPAN item is used to match or calibrate the
SureFlow velocity sensors to the average room pressure
velocity as measured by a portable air velocity meter.

A sensor zero should be established prior to adjusting the
sensor span (see Calibration section following menu item
listing).

NONE

Unit is
factory
calibrated.
No initial
adjustment
should be
necessary.

FLOW ZERO

FLOW
ZERO

The FLOW ZERO item is used to establish the flow station zero
flow point. A zero or no flow point needs to be established prior
to using the flow measurement output (see Calibration section
following menu item listing).

All pressure based flow stations need to have a FLOW ZERO
established on initial set up. Linear flow stations with a 1-5 VDC
output also need to have a FLOW ZERO established. Linear
flow stations with a 0-5 VDC output do not need a FLOW
ZERO.

NONE

ELEVATION

ELEVATION

The ELEVATION item is used to enter the elevation of the
building above sea level. This item has a range of 0 to 10,000
feet in 1,000 foot increments. The pressure value needs to be
corrected due to changes in air density at different elevations.

0 to 10,000 feet above

sea level

0

22 Part Two

CALIBRATION MENU

MENU ITEM

SOFTWARE

NAME

ITEM DESCRIPTION

ITEM RANGE

DEFAULT

VALUE

ACCESS
CODE

ACCESS
CODE

The ACCESS CODE item selects whether an access code
(pass code) is required to enter the menu. The ACCESS CODE
item prevents unauthorized access to a menu. If the ACCESS
CODE is ON a code is required before the menu can be
entered. Conversely, if the ACCESS CODE is OFF no code is
required to enter the menu.

ON or OFF

ON

END OF
MENU

The END OF MENU item informs the user that the end of a
menu has been reached. The user can either scroll back up the
menu to make changes, or press the SELECT or MENU key to
exit out of the menu.

Technical Section 23

INTERFACE MENU

MENU ITEM

SOFTWARE

NAME

ITEM DESCRIPTION

ITEM RANGE

DEFAULT

VALUE

NETWORK
PROTOCOL

NET
PROTOCOL

The NET PROTOCOL item selects the communications
protocol used to interface with the building management
system.

MODBUS

or

CIMETRICS

MODBUS

NETWORK
ADDRESS

NET
ADDRESS

The NET ADDRESS item is used to select the main network
address of the individual room pressure device. Each unit on
the network must have its own unique address. The values
range from 1-247. If RS-485 communications are being used,
then a unique NET ADDRESS must be entered into the unit.

There is no priority between the RS-485 and keypad. The most
recent signal by either RS-485 or keypad will initiate a change.

RS-485 communications allows the user access to all menu
items except calibration items. The RS-485 network can initiate
a change at any time.

1 to 247

1

OUTPUT
RANGE

OUTPUT
RANGE

The OUTPUT RANGE item selects the resolution range of the
analog pressure signal output. There are two choices:

LOW -0.01000 to +0.01000 “H20.
HIGH -0.10000 to +0.10000 “H20.

0 volt / 4 mA represents maximum negative pressure
differential.
5 volts / 12 mA represents a 0 room pressure differential.
10 volts / 20 mA represents maximum positive pressure
differential.
If the actual pressure exceeds the range, the output remains at
maximum or minimum depending on direction of flow.

The SureFlow monitor updates the analog output every 0.1
second. This signal outputs a linear 0 to 10 volt direct current
(VDC) or 4 to 20 mA DC analog output which corresponds to
the measured room pressure.

LOW or HIGH

HIGH

24 Part Two

INTERFACE MENU

MENU ITEM

SOFTWARE

NAME

ITEM DESCRIPTION

ITEM RANGE

DEFAULT

VALUE

OUTPUT
SIGNAL

OUTPUT
SIG

The OUTPUT SIG item selects the type of analog pressure
signal output. The analog output signal can either be 0 to 10
VDC or 4 to 20 mA.

0 to 10 VDC or

4 to 20 mA

0 to 10 VDC

ACCESS
CODE

ACCESS
CODE

The ACCESS CODE item selects whether an access code
(pass code) is required to enter the menu. The ACCESS CODE
item prevents unauthorized access to a menu. If the ACCESS
CODE is ON a code is required before the menu can be
entered. Conversely if the ACCESS CODE is OFF no code is
required to enter the menu.

ON or OFF

OFF

END OF
MENU

The END OF MENU item informs the user that the end of a
menu has been reached. The user can either scroll back up the
menu to make changes, or press the SELECT or MENU key to
exit out of the menu.

25

Calibration

The calibration section explains how to calibrate the SureFlow pressure sensor, including
setting the proper elevation, and how to zero a flow station.

NOTE: The SureFlow pressure sensor is factory calibrated and normally does not need

to be adjusted. However, inaccurate readings may be detected if pressure
sensor is not installed correctly, or problems with the sensor exists. First check
that the sensor is installed correctly (usually only a problem on initial set up).
Second, go into DIAGNOSTICS menu, SENSOR STAT item. If NORMAL is
displayed, calibration can be adjusted. If an error code is displayed, eliminate
error code and then verify pressure sensor needs adjustment.

All pressure transducer based flow stations and 1 to 5 VDC linear flow stations
must be zeroed upon initial system setup. Linear 0 to 5 VDC flow stations do not
require a zero flow to be established.

Adjusting the SureFlow monitor calibration may be required to eliminate errors due to
convection currents, HVAC configuration, or equipment used to make the measurement.
TSI recommends always taking the comparison measurement in the exact same location
(i.e., under the door, middle of door, edge of door, etc.). A thermal air velocity meter is
needed to make the comparison measurement. Normally the velocity is checked at the

crack under the doorway, or the door is opened 1” to allow alignment of the air velocity

probe making the measurement. If the crack under the door is not large enough, use the
1” open door technique.

Calibrating pressure sensor - primary sensor or second sensor

Enter calibration menu (see Software Programming if not familiar with key stroke
procedure). Access code is turned on so enter proper access code. All menu items
described below are found in CALIBRATION menu.

Elevation

The ELEVATION item eliminates pressure sensor error due to elevation of
building. (See ELEVATION item in Menu and Menu items section for further
information).
Enter the ELEVATION menu item. Scroll through the elevation list and select the
one closest to the building’s elevation
Press the SELECT key to save the data and exit back to the calibration menu.

Sensor zero

Slide open pressure sensor door and tape over 1/2 inch sensor orifice (see
Figure 6). Make sure pressure sensor orifice is taped over. Sensor is located
about 3/4” into housing.
Select SENSOR ZERO item.
Press SELECT key. Sensor zero procedure, which takes 120 seconds, is
automatic.
Press SELECT key to save the data.
Remove tape from sensor orifice and close pressure sensor door.

Technical Section

Sensor span

NOTE: Always take a sensor zero prior to adjusting the sensor span. A smoke

WARNING: The span can only be adjusted in the same pressure direction.

Perform a smoke test to determine pressure direction.
Select SENSOR SPAN item.
Position thermal air velocity meter in door opening to obtain velocity reading.

Press / keys until pressure direction (+/-) and sensor span match thermal air
velocity meter, and smoke test.

test and a comparison measurement by an air velocity meter are
required to calibrate the pressure sensor. The air velocity meter only
gives a velocity reading, so a smoke test must be performed to
determine pressure direction.

Adjusting span cannot cross zero pressure. Example: If unit
displays +0.0001 and actual pressure is -0.0001 do not make
any adjustments. Manually change the air balance, close or
open dampers, or open door slightly to get both unit and actual
pressure to read in same direction (both read positive or
negative). This problem can only occur at very low pressures so
slightly changing the balance should eliminate the problem.

Press SELECT key to save sensor span.
Exit menu, calibration is complete.

Figure 6: Pressure sensor door slid open

Flow station pressure transducer zero

NOTE: Not required for linear flow stations with 0 to 5 VDC output.

Pressure based flow station

Disconnect tubing between pressure transducer and flow station.
Enter calibration menu. Access code is required.
Select FLOW ZERO to take flow zero.
Press SELECT key. Flow zero procedure, which takes 10 seconds, is automatic.
Press SELECT key to save data.
Connect tubing between pressure transducer and flow station.

26 Part Two

27

Linear flow station 1-5 VDC output

Remove flow station from duct, or cutoff flow in duct. Flow station must have no

flow going past sensor.
Enter calibration menu. Access code is required.
Select FLOW ZERO to take flow zero.
Press SELECT key. Flow zero procedure, which takes 10 seconds, is automatic.
Press SELECT key to save data.
Install flow station back in duct.

Technical Section

Maintenance and Repair Parts

The Model 8635 SureFlow Room Pressure Monitor requires minimal maintenance.
Periodic inspection of system components as well as an occasional pressure sensor
cleaning are all that are needed to insure that the Model 8635 is operating properly.

System Component Inspection

It is recommended that the pressure sensor be periodically inspected for accumulation of
contaminants. The frequency of these inspections is dependent upon the quality of the air
being drawn across the sensor. Quite simply, if the air is dirty, the sensors will require
more frequent inspection and cleaning.

Visually inspect the pressure sensor by sliding open the sensor housing door (Figure 7).
The air flow orifice should be free of obstructions. The small ceramic coated sensors
protruding from the orifice wall should be white and free of accumulated debris.

Figure 7: Pressure sensor door slid open

Periodically inspect the other system components for proper performance and physical
signs of excessive wear.

Pressure Sensor Cleaning

Accumulations of dust or dirt can be removed with a dry soft-bristled brush (such as an
artist's brush). If necessary, water, alcohol, acetone, or trichlorethane may be used as a
solvent to remove other contaminants.

Use extreme care when cleaning the velocity sensors. The ceramic sensor may break if
excessive pressure is applied, if sensor is scraped to remove contaminants, or if the
cleaning apparatus abruptly impacts the sensor.

WARNING: If you are using a liquid to clean the sensor, turn off power to the Model

8635.
Do not use compressed air to clean the velocity sensors.
Do not attempt to scrape contaminants from the velocity sensors. The

velocity sensors are quite durable; however, scraping may cause
mechanical damage and possibly break the sensor. Mechanical damage
due to scraping voids the pressure sensor warranty.

28 Part Two

29

Part Number

Description

800222

Model 8635 Pressure Monitor

800326

Pressure Sensor

800248

Sensor Cable

800414

Transformer Cable

800420

Transformer

Replacement Parts

All components of the room pressure monitor are field replaceable. Contact TSI HVAC
Control Products at [phone] (U.S. and Canada) or (001 651) 490-2811 (other
countries) or your nearest TSI Manufacturer's Representative for replacement part
pricing and delivery.

Troubleshooting Section

The SureFlow Room Pressure Monitor is designed to be trouble free. However,
installation problems or interaction with other HVAC components may cause system
problems. The SureFlow system is easy to trouble shoot if an organized approach to
evaluate the system is taken. Troubleshooting is broken down into hardware and
software problems. Hardware problems deal with the physical installation of the device.
Hardware problems include wiring problems, incorrectly installed equipment, and add­ons or non TSI equipment. Software problems include configuration problems, or
interaction problems with the HVAC system.

The hardware test described in this section determines that all TSI mechanical
components are functioning correctly. The hardware test requires the diagnostics menu
items to be accessed. If you are unfamiliar with the SureFlow monitor menus, see

Software Programming for keystroke procedure. Troubleshooting the majority of

problems is usually quick if the hardware test is followed.
Software and hardware problems are covered in the troubleshooting chart. Pick the

problem that most closely resembles your problem and review the possible symptoms
and corrective action. Software or system performance problems can and are affected by
the supply air system, exhaust air system, or physical configuration of the room.
Separating TSI system problems from the HVAC system can sometimes be difficult. TSI
recommends confirming all hardware is operating correctly before troubleshooting
software problems.

Hardware Test

Three tests need to be performed in order to determine all hardware is functioning
correctly. The tests are broken down into:

 Confirming wiring is correct.
 Confirming physical installation is correct.
 Verifying mechanical components.

Technical Section

Confirming wiring is correct

The most common problem with installed hardware equipment is incorrect wiring. This
problem usually exists on initial installation, or when modifications to the system take
place. The wiring should be very closely checked to verify it exactly matches the wiring
diagram. The TSI cables are all color coded to ensure proper wiring. A wiring diagram is
located in Appendix B of this manual. Wiring associated with non TSI components should
be closely checked for correct installation. If non TSI components are installed, consider
disconnecting them for testing purposes.

Confirming physical installation is correct

All of the hardware components need to be installed properly. Review the installation
instructions and verify components are installed properly at the correct location. This is
easily done when the wiring is checked.

Verifying mechanical components

Verifying all TSI components are operating correctly requires following a simple
procedure. The fastest procedure to confirm all equipment is operating is to first test the
DIM, and then go into the diagnostic menu to test each component.

NOTE: These tests require power to the units, so if unit has no power, refer to hardware

troubleshooting chart to eliminate power problem.

TEST - DIM

Press TEST key to verify Digital Interface Module (DIM) electronics are functioning
correctly. At the end of the self test, the display will show SELF TEST - PASSED if
all DIM electronics are good. If unit displays DATA ERROR at the end of the test,
the electronics may be corrupted. Check all software items to determine cause of
DATA ERROR.

If SELF TEST - PASSED is displayed proceed to test individual components. Enter

Diagnostics Menu and check the following:

 Sensor input.
 Sensor status.
 Analog output.

These diagnostic menu items are explained in detail in the next section
(Diagnostics Menu) of the manual, so their function is not reviewed here. If the
SureFlow system passes each of the tests, the mechanical piece parts are all
functioning correctly.

TEST - Sensor input

Enter SENSOR INPUT menu item in diagnostics menu. A voltage between 0 and
10 volts DC will be displayed. It is not important what the exact voltage is to pass
this test. Tape over the pressure sensor (slide pressure sensor door open) and
voltage should read approximately 5 volts (zero pressure). Remove tape and blow
on sensor. Displayed value should change. If voltage changes, the unit passes. If
voltage doesn’t change, proceed to TEST - Sensor status.

TEST - Sensor status

Enter SENSOR STAT menu item in diagnostics menu. If NORMAL is displayed,
the unit passes test. If an error message is displayed, go to diagnostics menu
section of the manual, SENSOR STAT menu item for explanation of error
message.

TEST - Analog output

30 Part Two

31

NOTE: This test is only performed if analog output feature is being used.
Enter ANALOG OUT menu item in diagnostics menu. A value between 0 and 255

will be displayed. Hook up a DC voltmeter to pins 9 and 10. Press the / keys to
change output from 0 to 255. Voltage should change from 10 volts to zero volts (20
mA to 0 mA if current output).

TEST - Flow station

Enter FLOW INPUT menu item in diagnostics menu. A voltage between 0 and 5
volts DC will be displayed. The exact voltage displayed is not important as long as
the voltage varies as flow changes. Zero volts equals no flow while 5 volts is
maximum flow. The signal is linear, so a correlation between flow and voltage can
be established.

If unit passed all tests, the mechanical components are physically working. If problems
still exist, go to troubleshooting chart for additional information, on both hardware and
software symptoms.

Diagnostics Menu

The items in the diagnostic menu aid in identifying problems the staff may encounter. The
items in this menu temporarily change the function by pressing the / keys. No
permanent change occurs with these menu items. Items are exited by pressing the

MENU key. When an item is exited the SureFlow monitor returns to its normal state.
Sensor Input

Menu item - SENSOR INPUT

The SENSOR INPUT item is used to verify that the DIM is receiving a signal from
the sensor. When this item is entered, a voltage will be indicated on the display.
The exact voltage displayed is relatively unimportant. It is more important that the
voltage is changing which indicates the sensor is working correctly.
0 volts represents a negative pressure of -0.2 inches H2O.
5 volts represents 0 pressure.
10 volts represents a positive pressure of +0.2 inches H2O.

Sensor Communications

Menu Item - SENSOR STAT

The SENSOR STAT item verifies that the RS-485 communications between the
pressure sensor and DIM is working correctly. Sensor error messages do not
display on DIM except when SENSOR STAT item is selected. The item will
display NORMAL if communications are established correctly. If problems exist,
one of four error messages will display:

COMM ERROR - DIM cannot communicate with sensor. Check all wiring

and the pressure sensor address. Address must be 1
(Figure 9).

SENS ERROR - Problem with sensor bridge. Physical damage to pressure

sensor or sensor circuitry. Unit is not field repairable.
Send to TSI for repair.

CAL ERROR - Calibration data lost. Sensor must be returned to TSI to

be calibrated.

DATA ERROR - Problem with EEPROM, field calibration, or analog output

calibration lost. Check all data programmed and confirm
unit is function correctly.

Analog Output

Menu Item - ANALOG OUT

Technical Section

The ANALOG OUT item is used to vary the analog output from the SureFlow

unit. When this item is entered, a number will be shown on the display indicating
the last analog output value. The value displayed ranges from 0 to 255. The
value 255 corresponds to the lowest voltage (current) output and 0 corresponds
to the highest voltage (current) output. Pressing the  key will decrease the

analog output and increase the value displayed. Pressing the  key will
increase the analog output and decrease the value displayed.

The ANALOG OUT function can be used in conjunction with a volt meter to verify

the analog output is correct.

Switch Input

Menu Item - SWITCH INPUT

The SWITCH INPUT item reads the input of the SWITCH IN contact pins 11 and

12. When this item is entered, the display will indicate either open or closed. If
the display indicates open, the DIM is in LOW ALARM, HIGH ALARM and
ALARM DELAY mode. If the display indicates closed, the DIM is in REM LOW
ALM, REM HIGH ALM, and DOOR DELAY mode.

SWITCH INPUT changes both alarm and alarm delay when closed. If the same
alarm or alarm delay is required, set both alarms or delays to same value.

Flow Input

Menu Item - FLOW INPUT

The FLOW INPUT item is used to read the input from the flow station. When this
item is entered, a voltage will be indicated on the display. The exact voltage
displayed is relatively unimportant. It is more important that the voltage is
changing which indicates the flow station is working correctly.

0 volts displayed equals zero flow.
5 volts displayed equals 2832 ft/min x duct area (ft2) - pressure based

flow station.

5 volts displayed equals TOP VELOCITY x duct area (ft2)- linear flow

stations (see Configure menu, TOP VELOCITY item).

Low Alarm Relay

Menu Item - LOW ALM REL

The LOW ALM REL item is used to change the state of the low alarm relay.
When this item is entered, the display will indicate either OPEN or CLOSED.
The / keys are used to toggle the state of the relay. The  key is used to
OPEN the alarm contact. The  key is used to CLOSE the alarm contact. When
the contact is closed, the LOW ALM REL should be in an alarm condition.

High Alarm Relay

Menu Item - HIGH ALM REL

The HIGH ALM REL item is used to change the state of the high alarm relay.
When this item is entered, the display will indicate either OPEN or CLOSED. The
/ keys are used to toggle the state of the relay. The  key is used to OPEN
the alarm contact. The  key is used to CLOSE the alarm contact. When the
contact is closed, the HIGH ALM REL should be in an alarm condition.

32 Part Two

33

Access Code

Menu Item - ACCESS CODE
The ACCESS CODE item selects whether an access code (pass code) is required to
enter the menu. The ACCESS CODE item prevents unauthorized access to a menu. If
the ACCESS CODE is ON, code is required before the menu can be entered.
Conversely, if the ACCESS CODE is OFF, no code is required to enter the menu.

Technical Section

Symptom

Possible Cause

Corrective Action

Display is blank.

Fuse is blown.

No power to DIM.

DIM is defective.

Measure voltage at pins 1 and 2 on DIM.
The voltage should nominally be 24 to 30 VAC.

If correct voltage is measured, internal DIM fuse is
probably blown. Unplug 14-pin connector from DIM for 2
minutes. The internal fuse will automatically reset. Plug
unit back in and check display. If display is still blank,
check all wiring, etc. If no problems are found, replace
DIM.

If zero volts are measured, see No power to DIM.
Verify circuit breaker is on.

Verify transformer primary measures 110 VAC.
Verify transformer secondary measures 24 to 30 VAC.

If proper voltage is found between pins 1 and 2 of the
DIM, all wiring has been checked, fuses have been
reset, and screen is still blank, the DIM is probably
defective. Replace DIM.

Sensor does not
calibrate.

Incorrect pressure
sensor address.

Pressure sensor must have address of 1. Check
pressure sensor dip switches 5 & 6 and verify address 1
is correct (7 to12 must be OFF).

Figure 8: Pressure sensor DIP switch

Sensor
communications
not working.

Check SENSOR STAT item in diagnostics menu. If
NORMAL is displayed, sensor is okay, if COMM
ERROR is displayed, check wiring, pressure sensor
address, and that dip switch 1 & 2 are ON (Figure 8).

Troubleshooting Chart

34 Part Two

35

Symptom

Possible Cause

Corrective Action

Pressure sensor
red LED is
blinking (Figure

8).

Problem with
sensor (slow
uniform blink).

Communication
(fast burst of
non-uniform
blinking).

Red LED is
constantly on.

Check SENSOR STAT and confirm NORMAL is
displayed. If ERROR is displayed, correct error.

Unit is communicating with DIM. This is normal.

This is normal when no problems exist or when no
communication is occurring.

DIM always
displays 0.200
inches H2O.

Incorrect pressure
sensor output.

Pressure sensor must be set for 0 to 10 volt output, not
4 to 20 mA (do not confuse this output with DIM analog
output). Check pressure sensor dip switch 3 and make
sure it is OFF (see Figure 8).

DIM does not
respond to RS­485
communications.

Network protocol is
incorrect.

Incorrect network
address.

Incompatible
software.

Go into INTERFACE menu, NET PROTOCOL item.
The protocol must match host system. Select correct
interface.

The network address at the building automation system
and at the DIM must match. The network address must
be unique for each DIM.

Data sent to DIM may be in form that the SureFlow
monitor cannot recognize.

DIM displays
opposite
pressure signal.

Sensor direction is
incorrect.

Pressure sensor must have dip switch correctly set for
proper sign display. Verify dip switch 4 is ON when
sensor is mounted in the laboratory (controlled space),
and OFF when sensor is mounted in corridor (reference
space). See Figure 8.

Alarm relays
don't work.

Alarms are turned
off.

Incorrect wiring.

Relay may be
defective.

Press TEST key. The individual alarm set points will
display. If all alarm set points are zero, alarm relay is not
active, so relay will not be required to change state.

Check the wiring from SureFlow monitor relay's output
to the device that is connected to the relays.

Disconnect the wiring from relay contact pins 13 and 14
for low alarm relay and pins 25 and 26 for high alarm
relay. Go into DIAGNOSTICS menu, LOW ALM REL or
HIGH ALM REL. Connect an ohmmeter to relay
terminals to verify contact open and closes. Press
the/ key to manually trip the relay. If relay responds
(contact opens and closes), the device connected is
incompatible or defective. If relay doesn’t respond, relay
is defective (may be caused by incompatible device).
Replace DIM.

Technical Section

Symptom

Possible Cause

Corrective Action

"DATA ERROR"
flashing on
display.

DIM was hit by
electrical
disturbance.

All data may be lost or changed. Review all
configuration parameters. DATA ERROR is removed
by pressing the RESET key.

Displayed
pressure wildly
fluctuating.

Exhaust or supply
system unstable.

Supply or exhaust
air is affecting the
sensor.

Check supply and exhaust flow for stability. Verify
reference pressure is not fluctuating.

Check location of supply air diffusers and exhaust
grilles. They should be as far from pressure sensor as is
realistic, 6 feet preferred, 2½ feet minimum. Supply
diffuser terminal throw velocity must be less than
10 ft/min at the sensor. Relocate supply or exhaust as
needed.

36 Part Two

37

Appendix A

Specifications

Room Pressure Module

Display

Range ................................................................... -0.20000 to +0.20000 inches

H2O

Resolution ............................................................ 5% of reading

Display Update ..................................................... 0.5 sec

Inputs

Switch in ............................................................... SPST (N.O.) Switch. Closing

Flow in ................................................................. 0 to 5 VDC

Outputs

Low Alarm Range ................................................ -0.19500 to +0.19500 inches

H2O

High Alarm Range ................................................ -0.19500 to +0.19500 inches

H2O

Alarm Contacts..................................................... SPST (N.O.) Max current 5A,

Analog Output

Type .......................................................... 0 to 10 VDC or 4 to 20 mA

Range ....................................................... High -0.100 to +0.100 inches

H2O

Resolution ................................................. 1.0% of range for 0-10 VDC

RS-485 ................................................................. Yes

Operating Temperature ........................................ 32 to 120°F

Input Power .......................................................... 24 VAC, 5 watts max

Dimensions .......................................................... 4.9 in. x 4.9 in. x 1.35 in.

Weight .................................................................. 0.7 lb.

Pressure Sensor

Temperature Compensation Range .................... 55 to 95°F

Power Dissipation ................................................ 0.16 watts at 0 inches H2O,

Dimensions (D x H) .............................................. 5.58 in. x 3.34 in. x 1.94 in.

Weight .................................................................. 0.2 lb.

switch initiates condition.

max voltage 150 VDC, 250
VAC. Maximum switch load 10
mA, 5 VDC. Contacts close in
alarm condition.

Low -0.0100 to +0.0100 inches
H2O

1.2% of range for 4-20 mA

0.20 watts at 0.00088 inches
H2O

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38 Appendix A

39

PIN #

DIM
Input / Output /
Communication

Description

1, 2

Input

24 VAC to power Digital Interface Module (DIM) and
sensor.
NOTE: 24 VAC becomes polarized when connected to
DIM.

3, 4

Output

24 VAC power for Pressure Sensor

5, 6

Input

0 to 10 VDC pressure sensor signal

7, 8

Communications

RS-485 communications between DIM and pressure
sensor

9, 10

Output

0 to 10 VDC / 4 to 20 mA pressure differential signal

11, 12

Input

Non powered switch input - When input is closed these
software items are enabled: REMOTE LOW ALARM,
REMOTE HIGH
ALARM, and DOOR DELAY.

13, 14

Output

Low alarm relay - N.O., closes in low alarm condition.

- See menu items LOW ALARM REMOTE LOW ALARM

15, 16

Communications

RS-485 communications between DIM and host building
automation system.

17, 18
19, 20

--

No function in this unit.

21, 22

Input

0 to 5 VDC flow station signal - supply or exhaust duct.

23, 24

--

No function in this unit.

25, 26

Output

High alarm relay - N.O., closes in high alarm condition.

- See menu items HIGH ALARM, REMOTE HIGH
ALARM

Appendix B

Wiring Information

Back Panel Wiring

WARNING: The wiring diagram shows polarity on many pairs of pins: ±, H / N, A / B.

Damage to the DIM may occur if polarity is not observed.

40 Appendix B

41

Appendix C

Access Codes

These are the access codes to the different menus of the SureFlow monitor. When an access
code is required, pressing the following key sequence will provide access to the required menu.

Key # Alarm Configure Calibration Interface Diagnostics

1 TEST EMERGENCY AUX TEST TEST
2 TEST MENU MENU EMERGENCY MUTE
3 MUTE AUX MUTE AUX AUX
4 EMERGENCY MENU MENU MUTE AUX
5 MENU MENU AUX MENU MENU

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42 Appendix C

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