Dwyer instruments, inc – Dwyer TFLS2 User Manual

Page 2

FUNCTIONAL DESCRIPTION
FSH High Level Fail Safe Protection
OUTPUT MODE is located at FSH. The tuning fork is installed at a high level position.
1. Relay Contact Output
A. Normal Status: SIGNAL light on means that the tuning fork is at normal status.

The sensor probe does not come in contact with the medium and relay NO and
COM are conductive.

B. Failure Status: Under the power failure, SIGNAL light off means that the tuning

fork locates at the failure status. At the same time, relay NC and COM are
conductive. In other words, if the sensor probe contacts with the medium, that
means the medium is higher than the high level.

FSL Low Level Fail Safe Protection
OUTPUT MODE is located at FSL. The tuning fork is installed at a low level position.
1. Relay Contact Output
A. Normal Status: SIGNAL light on means that the tuning fork is covered by the

medium, and the relay NO and COM contact are conductive.

B. Failure Status: Under the power failure, SIGNAL light off means that the tuning fork

locates at the failure status. At the same time, relay NC and COM are conductive.

In other words, if the sensor probe does not come in contact with the medium, that

means the medium is lower than the low level.

INSTALLATION
HORIZONTAL INSTALLATION
1. Do not install near substance inlet.

2. Conduit faces downward at installation.

3. The surface of the two fork blades needs to be facing each other horizontally.

VERTICAL INSTALLATION
1. With high sensitivity, switching point is distanced .59 in (15 mm) away from the tip

of fork.

2. Opening of the two fork blades is to be as the flow direction.

3. Do not install near the substance inlet.

MAINTENANCE/REPAIR
Upon final installation of the Model TFLS2 no routine maintenance is required. The
Model TFLS2 is not field serviceable and should be returned if repair is needed. Field
repair should not be attempted and may void warranty.

WARRANTY/RETURN
Refer to “Terms and Conditions of Sales” in our catalog and on our website. Contact
customer service to receive a Return Goods Authorization number before shipping the
product back for repair. Be sure to include a brief description of the problem plus any
additional application notes.

DWYER INSTRUMENTS, INC.

Phone: 219/879-8000

www.dwyer-inst.com

P.O. BOX 373 • MICHIGAN CITY, INDIANA 46360, U.S.A.

Fax: 219/872-9057

e-mail: [email protected]

Printed in U.S.A. 12/12

FR# R4-444006-00 Rev. 3

Diagram of Relay Contact Output