TJERNLUND EF-6AUTO, EF-8AUTO Owner's Instructions Manual

DESCRIPTION & PURPOSE

The EF-AUTO Series Duct Booster® fans are designed to increase the flow of heated air in warm air heating systems or cooled air in
central air conditioning systems. The EF-AUTO Series include a 115 VAC power cord and built-in Pressure Response Control so they
can be automatically operated when the forced air system fan/blower is running.

SEQUENCE OF OPERATION

The EF-AUTO Series are controlled by an electronic Pressure Response Control (PRC). The PRC control senses positive pressure in
the duct work and turns the EF-AUTO Fan on when the forced air system fan/blower is running. The EF-AUTO fan will continue to run
after the forced air system fan/blower shuts off to continue to distribute warm or cool air to the room. NOTE: The PRC may momentarily
shut the EF-AUTO unit off while the forced air system fan/blower is running while it does a pressure check to determine if the EF-AUTO
should continue to run.

MOTOR SPECIFICATIONS & PERFORMANCE

1. Table is based on straight metal duct. 90 degree elbows are equivalent to 10 feet of straight duct. 45 degree elbows are equivalent
to 5 feet of straight duct. Performance is based on 70oF. standard air.

2. The number after the EF-matches the round duct diameter. Example: The EF-6AUTO connects to 6” round duct.

3. For complete dimensions and performance specifications visit www.tjernlund.com.

INSTALLATION

The EF-AUTO fans are usually used in branch ducts, not the main supply or “trunk line” duct. All models can be easily mounted in sheet
metal or flexible duct. DO NOT install the EF-AUTO Series fans where the temperature of air within the duct exceeds 150 degrees F.
This temperature would rarely be found on a forced air system. Locating the fan near the end of the duct will provide the most efficient
performance.

IMPORTANT: For proper operation of the PRC sensing control, do not install the EF-AUTO within 10 duct diameters from outlet end
supply register. For example, if the duct is 6”, 6 x 10 = 60” from outlet supply register.

FLEXIBLE DUCT (Diagram A)

Choose a seam or other point in the duct where the EF-Series fan will be mounted.
IMPORTANT: For proper operation of the PRC control do not install the EF-AUTO
within 10 duct diameters from outlet end supply register. For example if the duct is 6”,
6 x 10 = 60” from outlet supply register. Cut or separate the flexible duct and install
the fan with fan blade facing the direction of air flow, (See Diagram A). Seal both
sides with duct tape and/or a flexible duct clamp. Support with plumber’s strap or
other suitable method if necessary.

TJERNLUND PRODUCTS, INC.

1601 Ninth Street • White Bear Lake, MN 55110-6794
PHONE [phone] • [phone] • FAX [phone]
Visit our web site • www.tjernlund.com

READ OWNER’S INSTRUCTIONS CARE­FULLY PRIOR TO INSTALLATION.
THESE INSTRUCTIONS MUST REMAIN
WITH EQUIPMENT. DO NOT DESTROY.

AUTOMATIC

DUCT BOOSTER® MODELS

EF-6AUTO & EF-8AUTO

©2008 TJERNLUND PRODUCTS, INC. ALL RIGHTS RESERVED P/N: 8504157

EF-6 AUTO

120V 30 Watt 0.4A

150 CFM 100 CFM 90 CFM180 CFM

120VEF-8 AUTO 56 Watt

1.1A

300 CFM 250 CFM325 CFM 200 CFM

MOTOR

SPECIFICATIONS

MODEL

DUCT LENGTH AND AIR FLOW (Cubic Ft / Minute)

0 FEET 25 FEET 50 FEET 75 FEET

AIR FLOW

8050017 10/20/08

DIAGRAM A

SHEET METAL DUCT (Diagram B)

Choose a joint on the existing duct where the EF-Series fan will be mounted.
IMPORTANT: For proper operation of the PRC control do not install the EF-AUTO
within 10 duct diameters from outlet end supply register. For example if the duct is 6”,
6 x 10 = 60” from outlet supply register. Separate the existing duct sections at the joint.
Cut a piece of duct on the female side of the existing duct 1 inch shorter than the
shroud length of the EF-Series model being installed. NOTE: DO NOT CUT OFF A
PIECE OF EXISTING DUCT WHICH HAS THE CRIMPED END. Insert fan in duct with
fan blade facing the direction of air flow, (See Diagram B). Seal joints with duct tape. If
extra support is necessary, use screws provided. Support with plumber’s strap or other
suitable method if necessary.

TROUBLESHOOTING

Motor (M2)

Motor (M1)

FOLLOW THE STEPS BELOW FOR A NEW INSTALLATION:

It may be necessary to measure voltage during troubleshooting. Extreme caution must be exercised to prevent injury.
If EF-AUTO fan does not run when the forced air handler fan/blower is running, verify 115 VAC power is supplied to the outlet the

EF-AUTO is plugged into. If 115 VAC power is supplied to outlet and EF-AUTO does not run follow the steps below.
Block register at end of EF-AUTO duct run and turn on air handler fan/blower. If EF-AUTO turns on with register blocked, verify fur-

nace filter is clean. Replace filter if dirty and see if EF-AUTO turns on when air handler fan/blower is running. If filter is clean, move
EF-AUTO closer to the Air handler fan/blower to see if higher pressure turns EF-AUTO on. Proceed to next step if EF-AUTO does not
turn on.

CAUTION: You will need to check for voltage across PRC control to proceed. Pull motor leads off of M1 & M2 on PRC sensing con­trol. With forced air handler fan/blower running, check for 115 VAC across M1 & M2 on PRC sensing control, (See Diagram C). If volt­age is not present, contact Tjernlund Products, Inc. @ 800-255-4208 for further assistance.

FOLLOW THE STEPS BELOW FOR AN EXISTING INSTALLATION:

It may be necessary to measure voltage during troubleshooting. Extreme caution must be exercised to prevent injury.
If EF-AUTO fan does not run when the forced air handler fan/blower is running, verify 115 VAC power is supplied to the outlet the

EF-AUTO is plugged into. If 115 VAC power is supplied to outlet and EF-AUTO does not run follow the steps below.
IMPORTANT: Unplug EF-AUTO fan from outlet before proceeding. Use a small screw driver to carefully pry sensing tube off of PRC

sensing port while at the same time pulling on sensing tube, (See Diagram D). Use compressed air or blow in sensing tube going to
sampling port in EF-AUTO housing, (See Diagram E). Replace tubing, plug in EF-AUTO, wait 30 seconds and turn air handler
fan/blower on to see if EF-AUTO turns on. Proceed to next step if EF-AUTO does not turn on.

Block register at end of EF-AUTO duct run and turn on air handler fan/blower. If EF-AUTO turns on with register blocked, verify fur­nace filter is clean. Replace filter if dirty and see if EF-AUTO turns on when air handler fan/blower is running. If filter is clean, move
EF-AUTO closer to the Air handler fan/blower to see if higher pressure turns EF-AUTO on. Proceed to next step if EF-AUTO does not
turn on.

CAUTION: You will need to check for voltage across PRC control to proceed. Pull motor leads off of M1 & M2 on PRC sensing con­trol. With forced air handler fan/blower running, check for 115 VAC across M1 & M2 on PRC sensing control, (See Diagram C). If volt­age is present apply 115 VAC to motor leads to see if motor is defective. If voltage is not present, replace PRC control board or con­tact Tjernlund Products, Inc. @ 800-255-4208 for further assistance.

AIR FLOW

8050018 10/20/08

DIAGRAM B

DIAGRAM EDIAGRAM D

DIAGRAM C

USE COMPRESSED
AIR OR BLOW IN SENS­ING TUBE GOING TO
SAMPLING PORT IN
EF-AUTO HOUSING.

MEASURE FOR 115
VAC ACROSS M1 &
M2 WHILE AIR HAN­DLER FAN/BLOWER
IS RUNNING.

USE A SMALL SCREW
DRIVER TO CAREFUL­LY PRY SENSING TUBE
OFF OF PRC SENSING
PORT WHILE AT THE
SAME TIME PULLING
ON SENSING TUBE.