Oriflow Lynx, Cobra User Manual

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Operating Instructions for

Cobra and Lynx

Duct Leakage Testers

(Metric)

Table of Contents

Introduction

Introduction ……………………………………….…….. 2

Safety Precautions

Safety Precautions ………………………………….…. 2

Prior to Testing

Are You Using the Correct Tester? …………………… 3 System Preparation …………………….………………. 3

Power Requirements ………………………………….... 3

Extension Cord Requirements ……………………….... 4

Flex-Duct Length ………………………………………... 4

Determining Maximum Allowable Leakage ….……..... 4

Determining Which Orifice Plate to Use …………….... 5 - 6

Duct Leakage Test Setup and Procedure

Install Orifice Plate and Upper Tube Section ………… 7 - 8 Connect Flexible Duct to Orifice Tube ………………... 9 Connect Flexible Duct to Duct System ……………….. 9 System Test Pressure Connection ……………………. 10 Duct Leakage Test Setup (SUPPLY) …………………. 11 Duct Leakage Test Setup (RETURN/EXHAUST) …… 12 Zeroing Pressure Gauges ……………………………… 13 Avoiding Over-Pressurization ………………………….. 14 Obtaining System Test Pressure ……………………… 15 Determining Leakage Rate……………………………… 15 – 17

Troubleshooting

Can’t obtain system test pressure ……………………… 17

Zero reading on “DUCT SYSTEM” gauge ………….... 18

Zero reading on “ORIFICE TUBE” gauge …………….. 19

“ORIFICE TUBE” gauge reading maxed out………...... 19

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 lasercut 1.6 mm 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).

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

MaximumLeakageCapacity(L/s)*

Model

Lynx

Cobra

Panther

Rhino

*–Usingthelargestsizedorificeavailableforthemodellisted.

250Pa 500Pa. 1000Pa 1500Pa 2000Pa. 2500Pa 3000Pa 3500Pa 4000Pa.

260L/s 255L/s 215L/s 110L/s — — — — —

310L/s 305L/s 285L/s 220L/s 95L/s — — — —

635L/s 625L/s 570L/s 505L/s 415L/s 290L/s 125L/s — —

770L/s 730L/s 670L/s 630L/s 560L/s 490L/s 420L/s 310L/s 225L/s

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

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

Flow Control

Option

Full Load

Amps

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

Lynx or Cobra Slide Gate 115

Cobra Slide Gate 230

Cobra VFD 115

Cobra VFD 230

Flow Control

Option

Voltage

Extension Cord

Length (meters)

3 to 15 14

15 to 30 12

3 to 50 14

15 to 30 14

3 to 50 14

15 to 30 12

3 to 50 14

15 to 30 14

Wire Gauge

Flex-Duct Length Make sure you have enough flexible-duct with your tester for the job. Each tester includes 3.8 m, 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 specification is commonly used:

1. Pressure Classification (Class A, B, C or D)

If the specification uses SMACNA Leakage Class or Pressure Class, you will need to calculate the total duct system surface area.

Oriflow has FREE Adobe forms available that will calculate duct surface area given the duct shape, dimensions and length (www.oriflow.com/freeform). These forms also calculate Leakage Factor, allowable leakage and Pass/Fail criteria among other calculations.

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 1000 Pa pressure and the maximum allowable leakage is 165 L/s, you will need a 76 mm orifice plate if using the Cobra tester (see Table 6) or a 102 mm plate if using the Lynx tester (Table 7).

Table 4 – Tester Capacities using the 25 mm Orifice Plate

System Static

Pressure

(Pa)

250 500

750 1000 1250 1500 2000

Table 5 – Tester Capacities using the 51 mm Orifice Plate

System Static

Pressure

(Pa)

250

500

750 1000 1250 1500 2000

Minimum Leakage*

(L/s)

4.2 18 15

4.2 17 30

4.2 16 14

4.2 14 13

4.2 12 8

4.2 10 5

4.2 4.2 --

Minimum Leakage*

(L/s)

16 73 61 16 71 59 16 68 57 16 63 50 16 59 40 16 47 24 16 17 --

COBRA Tester

Maximum

Leakage

(L/s)

COBRA Tester

Maximum

Leakage

(L/s)

LYNX Tester

Maximum

Leakage (L/s)

LYNX Tester

Maximum

Leakage (L/s)

Determining Which Orifice Plate to Use (continued)

Table 6 – Tester Capacities using the 76 mm Orifice Plate

System Static

Pressure

(Pa)

250 500

750 1000 1250 1500 2000

Table 7 – Tester Capacities using the 102 mm Orifice Plate

System Static

Pressure

(Pa)

250

500

750 1000 1250 1500

2000

Minimum Leakage*

(L/s)

39 196 165 39 193 160 39 184 151 39 177 135 39 160 109 39 137 66 39 54 --

Minimum Leakage*

(L/s)

83 309 260 83 304 255 83 297 241 83 283 215 83 257 172 83 219 109

83 94 --

COBRA Tester

Maximum

Leakage

(L/s)

COBRA Tester

Maximum

Leakage

(L/s)

LYNX Tester

Maximum

Leakage (L/s)

LYNX Tester

Maximum

Leakage (L/s)

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

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

Connect Flexible Duct to Orifice Tube See Figure 5 below for securing one end of the flexible duct to the orifice tube. Note

that the worm-gear clamp should be slid over the flex-duct before connecting it to

the orifice tube. Slide the flexible duct so that it overlaps the orifice tube 50 to 75 mm, and tighten clamp using a 8 mm nut driver.

Figure 5 – Installing Flex-Duct on Tube

Connect Flex-Duct to Duct System Connect the 152 mm 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.

Figure 6 – Connection to Duct System

System Test Pressure Connection Refer to Figures 7 and 8. To monitor the system static pressure, you need to drill a 8 mm diameter hole at least 1 m away from the flex-duct connection. Next, insert the grey, plastic static pressure tap that is located on the end of the pressure tubing coming from the “DUCT SYSTEM” gauge. Seal the pressure tap to the duct wall using duct tape (Figure 7).

If the static pressure tap is missing, just insert end of pressure tubing from the “DUCT SYSTEM” gauge so that 150 to 305 mm of tubing is inside the duct system.

Using putty or duct tape, seal the connection. See Figure 8.

Figure 7 – Connection to Duct System using Static Pressure Tap

Figure 8 - Static Pressure Tubing Connection

DUCT SYSTEM pressure tubing inserted into duct system

Duct Leakage Test Setup (SUPPLY)

See Figure 9 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 9 – Duct Leakage Test Setup for a SUPPLY System

Duct Leakage Test Setup (RETURN/EXHAUST)

Refer to Figure 10 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 152 mm 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 10 – Duct Leakage Test Setup for a RETURN/EXHAUST System

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 11.

Figure 11 – 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

3. Press

4. Press

5. Press

6. Press MENU button two times to get back to the pressure reading.

7. Pressure should be reading zero or within +/- 4 Pa. If not, repeat steps.

▼ arrow button until Adu shows on screen.

E button once to go into auto-zero mode E button again and AUTO will be blinking on screen E button a third time to complete the zeroing process.

Avoid 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 powering up for the first time, the reading will already be at 10.00. See Figure 12.

Figure 12 – 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 (Figure 13) if your tester

has an inlet slide gate. If your tester has the VFD speed controller, press the green

until the readout shows 10.00 (the lowest speed setting). If

RUN button, and then press the UP arrow button

Pressing and holding the UP button Figure 13.

will increase speed more quickly. See

to increase fan speed.

Figure 13 – Obtaining System Test Pressure (inlet slide model on left, VFD speed control

model on right)

Obtaining System Test Pressure (continued) Regardless of tester model used, pay attention to the “DUCT SYSTEM” gauge while increasing airflow. When you have reached the required system static pressure, tighten the set-screw on the inlet damper (or STOP pressing the UP arrow button

on the speed controller).

Figure 14 – Duct System Gauge Reading (analog on left, digital on right)

Determining the Leakage Rate Now that you have obtained the system test pressure, note the pressure reading of

the ORIFICE PLATE gauge (Figure 15). 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 16; 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 15 –ORIFICE PLATE Gauge Reading (analog on left, digital on right)

SAMPLE CALIBRATION CERTIFICATE

USE YOUR CERTIFICATE

Figure 16 – Example Calibration Certificate. Use the calibration certificate that came with your orifice

plate

Example (refer to Figures 15 and 16) For an ORIFICE TUBE gauge reading of 725 Pa (Figure 15), the leakage

rate is approximately 235 L/s using the calibration certificate shown in Figure 16 (see arrow).

For an exact value, use the equation that comes with every calibration certificate. For the example shown in Figure 16:

Leakage = 8.733 x where the value of “8.733” 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 gauge reading first, and then multiply by the constant for your orifice plate (for this example, the constant is "8.733"). The exact leakage is 8.733 x (square root of 725) = 235.1 L/s.

Oriflow has a FREE Adobe format Duct Test Summary Sheet available that will

calculate the leakage, leakage factor, allowable leakage, Pass/Fail criteria and duct surface area among other variables (www.oriflow.com/freeform). Files are available

for SMACNA or DW/143 requirements.

Troubleshooting

Can’t obtain system test pressure (THIS IS THE MOST COMMON ISSUE)

This 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.

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 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 online at www.oriflow.com for more information.

Zero reading on “DUCT SYSTEM” gauge

If the gauge reading is zero, refer to the table below to fix this problem. Perform

troubleshooting steps in the order shown in the Table 7 below.

Table 7 –Troubleshooting steps when “DUCT SYSTEM” gauge is zero

Step Scenario What to do

Inlet damper was left shut,

cutting off air to the system.

Pressure tubing connected

to gauge incorrectly

Plugged fitting or

malfunctioning gauge.

System is leaking

too much air.

Open inlet damper slowly.

Look at the P1 and P2 stickers that are located on the orifice tube and gauges. Make sure tubing from P1 tap matches the P1 tap on the “ORIFICE TUBE” gauge.

Gently blow through other end of pressure tubing from “DUCT SYSTEM” gauge, and watch needle increase pressure reading.

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.

Zero reading on “ORIFICE TUBE” 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 TUBE” gauge is zero

Step Scenario What to do

2 Plugged pressure taps.

5 Malfunctioning gauge.

6 Not sure

Inlet damper was left shut,

cutting off air to the system.

Orifice plate too large for

application.

System is leaking very little

air.

Pressure tubing connected

incorrectly.

Open inlet damper slowly.

Remove pressure tubing from “ORIFICE TUBE” gauge, and blow through each end to make sure the pressure taps on the orifice tube are clear.

If you are using a 102 mm ID orifice plate, and the system is leaking 20 L/s, you probably won’t even notice the gauge needle moving. This will happen to larger orifice plates too. You need to use or purchase an orifice plate with a smaller bore diameter so that a small amount of airflow/leakage will result in a bigger pressure drop.

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 diameter.

Look at the P1 and P2 stickers that are located on the orifice tube and gauges. Make sure they match.

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.

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 TUBE”.

“ORIFICE TUBE” gauge reading maxed out

 Scenario 1: 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 curing time of 24 to 48 hours. Always refer to duct sealant manufacturer’s instructions.

 Scenario 2: orifice plate bore could be too small, causing a high pressure

drop at low to moderate flows. You need an orifice plate with a larger bore.

ORIFLOW LLC

www.oriflow.com

2125 Range Rd., Unit B Clearwater, Florida 33765 727-400-4881 (phone) 877-420-7091 (fax) sales@oriflow.com

Oriflow Lynx, Cobra User Manual

Specifications and Main Features

Frequently Asked Questions

User Manual