Time Mark 451 Data Sheet

MODEL 451

1

2 3

4

5

6

7

8

GND

4-20mA+24VDC

Pressure Transducer

⚫ 0-15 PSI air pressure input
⚫ 4-20mA output

⚫ Bubbler type system

⚫ Can be used with any controller

requiring a 4-20mA input

⚫ 5 Year Unconditional Warranty

⚫ Engineered and Built in the U.S.A.

DESCRIPTION

The Model 451 pressure transducer will convert

0-15psi to proportional 4-20mA signal. It can be used

with any pump control system that utilizes a

4-20mA input for level control. The 451 can be
mounted in a standard 8-pin octal socket for remote

use.

DIMENSIONS

SPECIFICATIONS

Model 451

Input voltage 24VDC
Power consumption 1 watt maximum
Air pressure input 0 to 15 psi
Max. air pressure 58 psid

Input air supply

fitting
Repeat accuracy ±1%
Signal output 4-20mA proportional to 0-15 psi

(in water; 0-15 psi = 0-34.6 feet at +77° F)

Max. load resistance 500 ohms

Compensated

temperature

Operating

temperature
Humidity tolerance 0-97% w/o condensation
Case material NORYL plastic
Termination *8-pin octal socket
Weight 3 oz.

requires 3/16” i.d. tubing

32° to +158° F

-13° to +158° F

*Order 8-pin socket number 51X120

PIN DRAWING

INSTALLATION

Mount the Model 451 in a suitable enclosure. An 8-pin
socket (Model 51X120) and a NEMA-1 rated enclosure,
designed for socket-mounted devices (Model ENC-1)
are available from Time Mark.

Connect the wiring as shown on the pin drawing or the

front of the unit.

Connect a 3/16” I.D. tubing to the input air supply fitting

09/2020

© 2020 TIME MARK CORPORATION

MODEL 451

Wet
Well

Air

Pump

Model

450

READ ALL INSTRUCTIONS BEFORE INSTALLING, OPERATING OR SERVICING THIS DEVICE.

Pressure Transducer

KEEP THIS DATA SHEET FOR FUTURE REFERENCE.

GENERAL SAFETY

POTENTIALLY HAZARDOUS VOLTAGES ARE PRESENT AT THE TERMINALS OF THE MODEL 451.

ALL ELECTRICAL POWER SHOULD BE REMOVED WHEN CONNECTING OR DISCONNECTING WIRING.

THIS DEVICE SHOULD BE INSTALLED AND SERVICED BY QUALIFIED PERSONNEL.

Installation Instructions

INSTALLATION (cont’d)

Connect a 3/16” I.D. tubing to the input air supply fitting
on the top of the unit. No connection is required on the
reference fitting. Connect the other end of the tubing to

the air compressor and the tank or well
(see figure 1).

Figure 1 Model 451 Application

Model

451

TROUBLESHOOTING

Should the Model 451 Pressure Transducer fail to
operate, check the power supply connections, making
sure that the polarity and voltage levels are correct.
Verify that all electrical connections are firmly attached
to the terminals. Check the full length of the air hose
and hose connections, to ensure there are no pressure
leaks. Connect a known pressure source to the INPUT
connection, while measuring the output current from
pins 5 and 4. The output current must have a complete
circuit through the controller, returning to the pressure
transducer. Should problems persist, contact the factory

for assistance.

WARRANTY

This product is warranted to be free from defects in
materials and workmanship, and is covered by our

exclusive 5-year Unconditional Warranty. Should this

device fail to operate for any reason, we will repair it for
five years from the date of manufacture. For complete
warranty details, see the Terms and Conditions of Sales
page in the front section of the Time Mark catalog or

contact Time Mark at 1-800-862-2875.

09/2020

© 2020 TIME MARK CORPORATION