Oriflow Cobra User manual
© Copyright 2018 ORIFLOW LLC
Operating Instructions for
Cobra and Lynx
Duct Leakage Testers
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
1
Links to Online Help
(QR Code)
Video – Commercial Duct Leakage
Testing
Online Technical Library
Online Max Leakage Calculator
(SMACNA Leakage Class)
Online Max Leakage Calculator
(% Allowable)
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
2
Table of Contents
Introduction
Introduction ……………………………………….………………………….…………… 3
Safety Precautions
Safety Precautions ………… READ FIRST! ……….….……………….……………… 3
Prior to Testing
Are You Using the Correct Tester? …………………………………….…...…………. 4
System Preparation …………………….……………….…………….……...….……… 4
Power Requirements …………………………………....…………….……...….……… 4
Extension Cord Requirements ………………………....…………….……...…………. 5
Flex-Duct Length ………………………………………...…………………….……...…. 5
Determining Maximum Allowable Leakage ….………..……………...…….….……… 5
FREE Oriflow duct test summary form (SMACNA or DW/143) ………….….………. 5
Determining Which Orifice Plate to Use ……………....……………..……..…………. 6 - 7
Duct Leakage Test Setup and Procedure
Install Orifice Plate and Upper Tube Section ……………………………..………..…. 8 - 9
Connect Flex-Duct to Orifice Tube ………………........…………….……...….……… 9
Connect Flex-Duct and Static Pressure Tap to Duct System ………….……………. 10 - 11
Duct Leakage Test Setup (SUPPLY) ………………….……………..……..…………. 12
Duct Leakage Test Setup (RETURN/EXHAUST) …………………..……..…………. 13
Zeroing Pressure Gauges ……………………………………………..……..…………. 14
Avoiding Over-Pressurization …………………………..……………...…….…………. 15
Obtaining System Test Pressure ……………………………………...…….…………. 15 - 16
Determining Leakage Rate……………………………………………..….….…………. 16 - 17
Troubleshooting
Can’t obtain system test pressure (DUCT PRESSURE TOO LOW) …………….…. 18
Can’t obtain system test pressure (DUCT PRESSURE TOO HIGH) …….……….… 19
Zero reading on ORIFICE PLATE gauge ……………..…………………........……….. 19
ORIFICE PLATE gauge reading maxed out ………......……………...….…....………. 20
GFCI/GFI trips …………………………………………………………………………….. 20
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
3
Introduction
These operating instructions are for ORIFLOW models COBRA and LYNX air leakage testers. Take
pride in knowing that you have purchased the best air leakage tester on the market. It is no secret that
Oriflow manufactures the highest quality testers, and has unparalleled customer service and technical
support.
The orifice plates available for your duct leakage tester are constructed from laser-cut 0.063-inch
stainless steel and do not require recalibration for 5 years. Note the authority having jurisdiction may
override this requirement, and if so, Oriflow has reasonable rates for re-calibrating orifice plates
manufactured by Oriflow.
Safety Precautions
Before operating your tester, read the following safety precautions:
DO NOT operate the tester in the rain,
DO NOT operate the tester while it is near or in water,
DO NOT operate the tester with a damaged electrical cord or plug,
DO NOT remove the inlet safety screen,
DO NOT touch the blower wheel when the unit is plugged in,
DO NOT look into the discharge end of the tester when the unit is plugged in,
DO NOT use the tester as a ladder or step stool,
DO NOT allow children near the tester,
DO use an extension cord of the proper gauge (see Table 2),
DO use the proper voltage and line frequency listed on the motor nameplate,
DO lock the caster when the tester is positioned horizontally,
DO use the tester on level ground,
DO secure the tester when transporting it,
DO wear proper hearing protection, safety glasses and work gloves,
DO seek assistance when lifting the tester (e.g., loading onto truck, going up or down stairs).
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
4
Prior to Testing
Are you Using the Correct Tester?
See Table 1 for the maximum capacity for each duct tester when using the largest orifice plate.
Table 1 – Duct Leakage Tester Capacities
Model
MaximumLeakageCapacity(cfm)*
SystemTestPressure(in.wg.)
0.101246 7 8 9 101214 16
Lynx570
cfm
550
cfm
540
cfm
455
cfm
290
cfm
160
cfm——————
Cobra680
cfm
650
cfm
645
cfm
600
cfm
465
cfm
405
cfm
350
cfm
250
cfm————
Panther1400
cfm
1350
cfm
1320
cfm
1210
cfm
1065
cfm
970
cfm
875
cfm
875
cfm
615
cfm
270
cfm——
Rhino1700
cfm
1630
cfm
1550
cfm
1420
cfm
1330
cfm
1255
cfm
1185
cfm
1185
cfm
1035
cfm
895
cfm
660
cfm
480
cfm
* Using the largest sized orifice available for the model listed.
System Preparation
Cap off all ends of system using clear plastic and duct tape or sheetmetal duct end caps. Make sure
you test the part of the duct system that leakage testing is required. Usually, this is from the system fan
up to, but not including, the VAV boxes (terminal units). Refer to the engineer's specifications and all
applicable codes and test standards.
Power Requirements
Do you have an adequate power supply for your tester (see Table 2)?
Table 2 – Tester Amp Draw
Tester Model Voltage Flow Control
Option Full Load
Amps
Lynx 115 Slide Gate 12.7
Cobra 115 Slide Gate 12.8
Cobra 115 VFD 14.0
Cobra 230 Slide Gate 6.4
Cobra 230 VFD 8.0
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
5
Extension Cord Requirements
If you need an extension cord, is it the proper gauge? See Table 3 below for extension cord
requirements.
Table 3 – Required Extension Cord Wire Gauge
Tester Model Flow Control
Option Voltage Extension Cord
Length (feet) Wire Gauge
Lynx or Cobra Slide Gate 115 10 to 50 14
50 to 100 12
Cobra Slide Gate 230 10 to 50 14
50 to 100 14
Cobra VFD 115 10 to 50 14
50 to 100 12
Cobra VFD 230 10 to 50 14
50 to 100 14
Flex-Duct Length
Make sure you have enough flexible-duct with your tester for the job. Each tester
includes 12.5 feet, which is enough for most applications. Extra lengths of flexible-duct
are available at www.oriflow.com/products.
Determining Maximum Allowable Leakage
To determine the maximum allowable leakage for the project, use ORIFLOW’s free
online programs to make these calculations (www.oriflow.com/programs).
In the U.S., calculations are done for either of the two typical specifications:
1. Percentage of system flow, or
2. SMACNA Leakage Class.
In Europe, Australia and other countries outside of the U.S., the following DW/143 specification is
commonly used:
1. Pressure Classification (Class A, B, C or D)
If the specification uses SMACNA Leakage Class or Pressure Classification, you will need to calculate
the total duct system surface area.
Oriflow has a FREE Adobe test summary sheet that will calculate duct surface area,
leakage, leakage factor, allowable leakage, and Pass/Fail criteria. You can find these
test summary sheets at (www.oriflow.com/freeform). It’s an excellent tool that can be
printed out or emailed to a customer or engineer for submittal.
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
6
Determining Which Orifice Plate to Use
After determining the allowable leakage at the system test pressure, refer to the following tables for the
capacities of each orifice plate available for the Cobra and Lynx model testers. The proper plate is the
one where the specified allowable leakage falls between the minimum and maximum leakage at the
system static pressure.
For example, if you are testing a system at 4 in.wg. pressure and the maximum allowable leakage is
350 cfm, you will need a 3-inch orifice plate if using the Cobra tester (see Table 6) or a 4-inch plate if
using the Lynx tester (Table 7).
Table 4 – Tester Capacities using the 1-inch Orifice Plate*
System Static
Pressure
(in.wg.)
Minimum
Leakage**
(cfm)
COBRA Tester
Maximum
Leakage
(cfm)
LYNX Tester
Maximum
Leakage
(cfm)
0.10 9 47 37
1 9 44 34
2 9 42 32
3 9 39 27
4 9 36 23
5 9 32 17
6 9 29 15
7 9 24 6
8 9 19 --
9 9 12 --
* If you need to measure lower flow rates, contact us about the
‘low-flow’ orifice plate.
** Recommended minimum based on 0.40 in.wg. across orifice
plate.
Table 5 – Tester Capacities using the 2-inch Orifice Plate
System Static
Pressure
(in.wg.)
Minimum
Leakage**
(cfm)
COBRA Tester
Maximum
Leakage
(cfm)
LYNX Tester
Maximum
Leakage
(cfm)
0.10 34 180 160
1 34 170 150
2 34 165 135
3 34 155 120
4 34 140 105
5 34 125 85
6 34 115 65
7 34 95 25
8 34 75 --
9 34 45 --
** Recommended minimum based on 0.40 in.wg. across orifice plate.
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
7
Determining Which Orifice Plate to Use (continued)
Table 6 – Tester Capacities using the 3-inch Orifice Plate
System Static
Pressure
(in.wg.)
Minimum
Leakage**
(cfm)
COBRA Tester
Maximum
Leakage
(cfm)
LYNX Tester
Maximum
Leakage
(cfm)
0.10 82 440 375
1 82 420 355
2 82 410 340
3 82 390 320
4 82 375 285
5 82 340 230
6 82 290 170
7 82 245 55
8 82 195 --
9 82 130 --
** Recommended minimum based on 0.40 in.wg. across orifice plate.
Table 7 – Tester Capacities using the 4-inch Orifice Plate
System Static
Pressure
(in.wg.)
Minimum
Leakage**
(cfm)
COBRA Tester
Maximum
Leakage
(cfm)
LYNX Tester
Maximum
Leakage
(cfm)
0.10 175 680 570
1 175 650 550
2 175 645 540
3 175 630 510
4 175 600 455
5 175 545 365
6 175 465 290
7 175 405 160
8 175 350 --
9 175 250 --
** Recommended minimum based on 0.40 in.wg. across orifice plate.
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
8
Duct Leakage Test Setup and Procedure
Install Orifice Plate and Upper Tube Section
The orifice plate that was determined from the previous section should now be installed with the serial
number facing upwards so the corresponding calibration certificate may be referenced after installation.
Refer to Figures 1 through 4.
Figure 1 – Install Orifice Plate and then Rotate Clockwise
Figure 2 – Rotate Orifice Plate Clockwise until it Locks in Place
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
9
Install Orifice Plate and Upper Tube Section (continued)
After the orifice plate is locked in place, place the upper tube section over the bolt/wing nut set, rotate
clockwise, and tighten wing nuts (Figures 3 and 4).
Figure 3 – Install Upper Tube Section and Rotate Clockwise
Figure 4 – Tighten Wing Nuts after Rotation
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
10
Connect Flex-Duct to Orifice Tube
See Figure 5 below for securing the 5-inch end of the flexible duct to the orifice tube. Slide the flexible
duct so that it overlaps the orifice tube 2 to 3 inches, and tighten clamp using a 5/16-inch nut driver.
Figure 5 – Installing Flex-Duct on Tube
Connect Flex-Duct and Static Pressure Tap to Duct System
Refer to Figures 6 and 7. Connect the 6-inch end of the flex-duct to the duct system. Find a convenient
location in the duct system where the tester has easy access. Make sure the connection is a sturdy,
sealed tight connection. You don’t want to create a leaky connection thereby adding to the system
leakage.
To monitor the system static pressure, you need to drill a 5/16-inch diameter hole for the grey plastic
static pressure tap to measure system static pressure (Figure 7).
If the static pressure tap is missing, locate the hole at least 3 feet away from flex-duct connection, and
insert the pressure tubing from the DUCT SYSTEM gauge so that 6 to 12 inches of tubing is inside the
duct system. Using putty or duct tape, seal the connection. See Figure 8.
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
11
Connect Flex-Duct and Static Pressure Tap to Duct System (continued)
Figure 6 – Connection to Duct System
Figure 7 – Connection to Duct System using Static Pressure Tap
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
12
Duct Leakage Test Setup (SUPPLY)
See Figure 8 for the test setup for SUPPLY duct system testing (positive pressure testing). On the
backside of the DUCT SYSTEM pressure gauge, move the pressure tubing to the pressure port labeled
SUPPLY SYSTEM.
Figure 8 – Duct Leakage Test Setup for a SUPPLY System
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
13
Duct Leakage Test Setup (RETURN/EXHAUST)
Refer to Figure 9 for the test setup required to measure air leakage of a RETURN/EXHAUST system
(negative pressure testing). On the backside of the DUCT SYSTEM pressure gauge, move the
pressure tubing to the pressure port labeled RETURN SYSTEM.
Connect the 6-inch end of the flex-duct to the inlet of the blower so that air from the system is drawn
into the blower. You will determine the leakage of the system since the air drawn from the blower is
discharged through the orifice plate which you are measuring.
Figure 9 – Duct Leakage Test Setup for a RETURN/EXHAUST System
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
14
Zeroing Pressure Gauges
Before you turn on the tester, make sure both gauges have been zeroed.
Zeroing Analog Gauges
Using a small slotted screwdriver, turn the zero-adjustment screw on the gauge until the needle
is aligned with the zero reading. Turning the screw clockwise increases the pressure reading;
turning it counterclockwise decreases the reading. See Figure 10.
Figure 10 – Zeroing Analog Gauges
Zeroing Digital Gauges
First, turn on both gauges by pressing the black (or red) button located on the backside of each
gauge.
Use the following steps to zero each digital gauge:
1. Press MENU button once.
2. Press
▼arrow button until Adu shows on screen.
3. Press
Ebutton once to go into auto-zero mode
4. Press
Ebutton again and AUTO will be blinking on screen
5. Press
Ebutton a third time to complete the zeroing process.
6. Press MENU button two times to get back to the pressure reading.
7. Pressure should be reading zero or within +/- 0.02 in.wg. If not, repeat steps.
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
15
Avoiding Over-Pressurization
Prior to starting the blower, shut the inlet slide gate on models without the speed controller option. For
models with the VFD speed controller, press and hold the DOWN button until the readout shows
10.00 (the lowest speed setting). If powering up for the first time, the reading will already be at 10.00.
See Figures 11.
Figure 11 – Avoid Over-Pressurizing by Minimizing Air Delivery upon Startup
(inlet slide model on left, VFD speed control model on right)
Obtaining System Test Pressure
Turn the blower on and slowly open the inlet slide gate if your tester has an inlet slide gate. If your
tester has the VFD speed controller, press the green RUN button, and then press the UP arrow button
to increase fan speed. Pressing and holding the UP button will increase speed more quickly.
See Figures 12.
Figure 12 – Obtaining System Test Pressure (inlet slide model on left, VFD
speed control model on right)
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
16
Obtaining System Test Pressure (continued)
Regardless of tester model used, pay attention to the DUCT SYSTEM gauge while increasing airflow
(Figures 13). When you have reached the required system static pressure, tighten the set-screw on the
inlet damper (or STOP pressing the UP arrow button ).
Figure 13 – Duct System Test Pressure (analog on left, digital on right)
Determining the Leakage Rate
Now that you have obtained the system test pressure, note the pressure drop of the ORIFICE PLATE
gauge (Figures 14). Refer to your calibration certificate to determine the leakage rate that corresponds
to the gauge reading. An example of a calibration certificate is shown in Figure 15; it is for informational
purposes only and used in the example shown on the next page. Always refer to the calibration
certificate(s) that came with your calibrated orifice plate(s).
Figure 14 – Orifice Plate Pressure Drop (analog on left, digital on right)
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
17
SAMPLE CALIBRATION CERTIFICATE
USE YOUR CERTIFICATE
Figure 15 – Example Calibration Certificate. Use the calibration certificate that came with your orifice plate
Example (refer to Figures 14 and 15)
For an ORIFICE PLATE pressure drop (gauge reading) of 2.46 in.wg. (Figure 14), the leakage rate is
approximately 210 cfm using the calibration certificate shown in Figure 15.
For an exact value, use the equation that comes with every calibration certificate. For the certificate
shown in Figure 15:
Leakage = 134.42 x ,
where the value of “134.42” is a constant and will be specific to the orifice plate used (every plate has
its own value; yours will be different).
Using a calculator, take the square root of the ORIFICE PLATE gauge reading first, and then multiply
by the constant for your orifice plate (for this example, the constant is "133.357"). The exact leakage is
134.42 x (square root of 2.46) = 210.8 cfm.
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 11/2018
18
Troubleshooting
Can’t obtain system test pressure (DUCT PRESSURE TOO LOW)
This typically happens when the system is leaking too much air. Make sure all outlets are sealed.
Check corners of rectangular duct for excessive leakage. Inspect all duct and fitting joints for leakage.
Make sure you seal all suspect joints and allow to cure 24 to 48 hours. Always refer to duct sealant
manufacturer’s instructions.
Perform troubleshooting steps in the order shown in the Table 7 below.
Table 7 –Troubleshooting steps when DUCT SYSTEM test pressure is too low
Step Scenario What to do
1 Allowable Leakage is
greater than capacity of
tester. Refer to page 4, “Are you using the correct tester.”
2 Inlet damper was left shut,
cutting off air to the system. Open inlet damper slowly.
3 Pressure tubing connected
to gauge incorrectly
Look at the P1 and P2 stickers that are located on the
orifice tube (airflow meter) and gauges. Make sure tubing
from P1 tap is connected to the P1 tap on the ORIFICE
PLATE gauge.
4 Plugged pressure port on
orifice tube
Remove pressure tubing from the P1 and P2 ports on the
ORIFICE PLATE gauge. Blow through each tubing end.
You should be able to blow air freely through both ports.
5 Malfunctioning gauge.
Attach pressure tubing to the port labeled “SUPPLY
SYSTEM.” Gently blow through other end of pressure
tubing. The pressure reading should increase.
6 System is leaking
too much air.
Check for these other sources of leakage:
Rectangular duct joints (check and seal corners),
Fire or smoke dampers,
Duct joints (pay particular attention to flex-duct
joints if they are part of the leak test),
VAV boxes (pay particular attention to parallel box
back draft dampers),
Built-up air handlers,
Plenums,
Uncured duct sealant blow-thru (follow
manufacturer instructions for cure time),
Improperly sealed or un-sealed joints,
Hot water coils and electric heaters,
Open duct end that was supposed to be
sealed/capped-off for the leak test.
A non-toxic smoke machine is an excellent tool for locating significant sources of leakage. Call
ORIFLOW at 727-400-4881 or to our website at www.oriflow.com for more information.
Operating Instructions for Cobra © Copyright 2018
and Lynx Duct Leakage Testers Rev: 01/2018
19
Can’t obtain system test pressure (DUCT PRESSURE TOO HIGH)
This typically happens on small or tight systems when using a duct tester without the VFD speed
controller. Testers equipped with the inlet slide gate damper always run at about 3500 rpm and are so
powerful, air pressure is generated even with the inlet damper completely shut.
Use a smaller orifice plate. If using the 1-inch plate, install the ½-inch plate which is used to
measure flow rates from 1 to 10 cfm.
Using duct tape, completely cover the upper orifice tube section, and then poke a hole in it with
a screwdriver or pen. Then install the flex-duct as usual. This will act as an outlet damper or
restriction. Now you can use the inlet damper to regulate flow.
Zero reading on ORIFICE PLATE gauge
If the gauge reading is zero, refer to the table below to fix this problem. Perform troubleshooting steps
in the order shown in Table 8 below.
Table 8 –Troubleshooting steps when ORIFICE PLATE gauge is zero
Step Scenario What to do
1 Inlet damper was left shut,
cutting off air to the system. Open inlet damper slowly.
2 Plugged pressure taps.
Remove pressure tubing from ORIFICE PLATE gauge, and
blow through each end to make sure the pressure taps on
the orifice tube are clear.
3 Orifice plate too large for
application.
If you are using a 4-inch ID orifice plate, and the system is
leaking 40 cfm, you probably won’t even notice the gauge
needle moving. This can happen to other orifice plates too.
You need to purchase an orifice plate with a smaller bore
diameter so that a small amount of airflow/leakage will
result in a bigger pressure drop.
4 System is leaking very little
air.
You’ll know if this is true if the fan inlet is almost shut. Not
likely unless system is small. Fix is to use plate with
smaller bore.
4 Pressure tubing connected
incorrectly.
Look at the P1 and P2 stickers that are located on the
orifice tube and the ORIFICE PLATE gauge. Make sure
they match.
5 Malfunctioning gauge.
Remove the clear pressure tubing from the lower pressure
tap on the orifice tube and blow through the end of the
tubing. The needle should move in response. If not, the
gauge is faulty.
6 Not sure
The best way to make sure that your tester is working
properly is to disconnect the flex duct from the system and
turn the blower on, and slowly open the inlet damper. If you
feel a lot of air coming out of the tube end, you should see
a pressure reading on the gauge ORIFICE PLATE.
Other manuals for Cobra
2
This manual suits for next models
1
Table of contents
Other Oriflow Test Equipment manuals
