Time Mark 272 Data Sheet

3.0"

5.5"

3.88"

.19 dia. typ.

6.06"

2.08"

.62"

MODEL 272

MAX CURRENT - MIN CURRENTMAX CURRENTMAX CURRENT

MAX CURRENTMAX CURRENTMAX CURRENT

100 = %

TIME MARK is a division of

3-Phase Current

Unbalance Detector

 Adjustable Trip Delay

 Adjustable Unbalance Percentage

 Automatic Reset

DESCRIPTION

The Model 272 3-Phase Current Unbalance Detector
monitors 3-phase lines to detect an unbalanced current. It can
also monitor three separate single phase lines for equal
current levels.

The percentage of unbalance is adjustable from 2% to 25% by
adjusting a front panel control. An unbalance greater than
this setting energizes the relay. The formula for an unbalance
is:

An adjustable trip delay of 0.5 to 10 seconds is also provided.
For optimum performance, operating currents should be kept
in the 1 to 5 amps range. However, zero current on each
phase is considered to be a balanced condition.

Continuous currents, up to 10 amps per phase, will not
damage the unit, nor will current surges up to 40 amps for 2
seconds. The contacts are automatically reset when the
unbalanced condition is corrected.

A supply voltage of 24 or 120VAC is required for this unit.

SPECIFICATIONS

Model 272-24 272-120

Input Voltage 24VAC 115VAC

Input Voltage Range 20-28VAC 100-130VAC

Power Consumption

VA Burden

Frequency Range 50 - 400Hz

Current Range 1 - 5 amps AC

Max. Input Current 40 amps for 2 seconds

Unbalance Adjustment 2% to 25%

Trip Delay

Contact Rating SPDT 10A at 240VAC resistive

Expected Relay Life Mech: 10 million operations

Elec: 100,000 at rated load
Transient Protection 2500V for 10ms

Operating Temperature - 20° to +131° F

Humidity Tolerance 0-97% w/o condensation

Enclosure Material ABS plastic

Weight

1.5W

0.5VA per phase

0.5 to 10 seconds ± 20%

1 lb. 1.5 oz.

DIMENSIONS

11/2011

© 2011 TIME MARK CORPORATION

Control
voltage

Start

Stop

AC

A B C

Motor

O/L's

MODEL 272

TIME MARK is a division of

3-Phase Current Unbalance Detector

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

KEEP THIS DATA SHEET FOR FUTURE REFERENCE.

GENERAL SAFETY

POTENTIALLY HAZARDOUS VOLTAGES ARE PRESENT AT THE TERMINALS OF THE MODEL 272.

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

THIS DEVICE SHOULD BE INSTALLED AND SERVICED BY QUALIFIED PERSONNEL.

Installation Instructions

INSTALLATION

Mount the Model 272 in a suitable enclosure.

Connect AC operating power to the appropriate
terminals.

Connect the normally closed (N.C.) relay contacts to the
load control wiring.

Connect the 3-phase currents or CT outputs to the
current input terminals marked A B C.

Set the PERCENT UNBALANCE and TRIP DELAY
adjustments to the desired levels, and apply operating
power.

TROUBLESHOOTING

Should the monitor fail to operate properly, check that
all three currents are present and are of the correct
level. Check all fuses and verify that all wiring
connections are correct. Should problems persist,
contact the factory at 800-862-2875 for assistance.

WARRANTY

This product is warranted to be free from defects in
materials and workmanship for one year. Should this
device fail to operate, we will repair it for one year 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.

TYPICAL APPLICATION

Shows No Power Applied

11/2011

© 2011 TIME MARK CORPORATION