TIME MARK 2744 User manual

SPECIFICATIONS
Model 2744-24 2744-120 2744-220
Supply voltage 20-28VAC 100-130VAC 190-250VAC
Max supply voltage 30V 140V 260V
Power consumption 1.5 Watts max.
Transient protection 2500 VRMS for 10 msec
Frequency range 50 -400 Hz
Input current 1-5 amps ±5%
Max. input current 40 amps for 2 sec
Current range 1-5 amps ± 5%
Start delay 5to 15 sec ± 5%
Dead band 4% max.
Contact rating DPDT 10A at 240 VAC resistive
Expected relay life
Mech: 10 million operations Elec: 100,000 ops at rated load
Operating temperature -40º to +131º F
Enclosure material ABS plastic
Weight 1 lb. 5.9 oz.
DESCRIPTION
The Model 27443-Phase Over Current Monitor is designed
to monitor the current level of a three-phase line or to compare
the currents of three single-phase lines.
If one or more current inputs rises above the trip level after the
start delay has expired, the internal relay will de-energize.
An adjustable start delay of 5to 15 seconds will prevent
nuisance trippingon start up. The current trip point is
adjustable from 1 to 5 amps, and matching current
transformers are available to extend the current range of the
monitor.
The Model 2744will automatically reset when the current fault
is corrected. An external manual reset can be added by
installing a normally closed switch between the terminals
marked RESET.
DIMENSIONS
ll Monitors over current
ll Fail-safe design
ll Automatic or manual reset
ll Adjustable start delay timer
ll For use on motors, pumps, conveyors, etc.
3.5 3.125
4.5
2.25
4.8
4.0
TYPICAL APPLICATION
Over-current; auto reset; ≤≤ 5 amps
MODEL 2744
3-Phase Over Current
Monitor
For Motor Jams
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August 2003
© 2003 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
Shows No Power Applied

INSTALLATION
Mount the Model 2744in a suitable enclosure.
If the current to be monitored is 5 amps or less, break and
connect each wire to the three inputs of the Model 2744(see
TYPICAL APPLICATION on front page). Observe polarity.
If the current to be monitored is greater than 5 amps,
install a current transformer on the line. Connect the
secondary leads of the CT to the Model 2744terminals (see
TYPICAL APPLICATION on this page). Observe polarity.
Connect the operating supply voltage to the AC input
terminals.
Connect the load control wiring to the appropriate terminals.
For most motor control applications, use the normally open
contact(s), which will close when the current is within the
acceptable range. For alarm applications, use the normally
closed contact(s). Refer to the diagram on this page.
If a manual reset is desired, connect a normally closed
push-button across the RESET terminals (see figure 1).
ADJUSTMENT PROCEDURE
Set the START DELAY adjustment to the required setting. If
the desired current trip level is known, set the CURRENT
adjustment to that point. A slight adjustment up or down may
be necessary to allow for tolerance inaccuracies.
Shows No Power Applied
WARRANTY
The Model 2744Over Current Monitor is warranted to be free
from defects in materials and workmanship for one year.
Should this device fail to operate, we will repair or replace 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.
TYPICAL APPLICATION
Over-current; auto reset; ≥≥ 5 amps
figure 1
C
B
A
AC RST
Reset
MANUAL RESET
MODEL 2744 3-Phase Over Current Monitor
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 2744.
ALL ELECTRICAL POWER SHOULD BE REMOVED WHEN CONNECTING OR DISCONNECTING WIRING.
THIS DEVICE SHOULD BE INSTALLED AND SERVICED BY QUALIFIED PERSONNEL.
Installation Instructions
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
E-mail: [e-mail]
Internet:http://www.time-mark.com
August 2003
© 2003 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116

2.19"
1.79"
.23"3.2"
3.65"
.30" x .19"
3.9"
.50" dia.
.95"
1.25"
2.66"
.76"
DESCRIPTION
The Model 1732 AC Current Monitor is a single
setpoint current monitor. It can be used to detect either
over current or under current, depending on whether the
trip point is set above or below the input current. Dual
LED indicators on the front or top of the unit give a clear
visual reference for a fault condition.
The Model 1732 generates it’s operating voltage from
the monitored current line, so no external power supply
is required. A current greater than 25 amps is needed
to energize the internal relay. The maximum current set
point is 150 amps.
The Model 1732 is not frequency sensitive, and can be
used on AC currents from 50 to 400 Hz.
Model 1732
Supply Voltage none required
Input Current Minimum: 25 amps
Maximum: 150 amps
Adjustment Range 25 to 150 amps
Maximum Wire Size 2 AWG
Response Time 100 msec
Contact Rating SPDT 10A at 240VAC resistive
Repeat Accuracy 1% max.
Dead Band Approximately 2%
Operating Temperature -40° to +140° F
Reset Automatic
Terminals 1/4” quick connects
Enclosure Material ABS plastic
Weight 3.5 oz.
SPECIFICATIONS
DIMENSIONS
TYPICAL APPLICATION
-Under current
MODEL 1732
AC Current Monitor
ll Detects Over or Under Current
ll Adjustable Setpoint
ll No External Power Supply
ll Dual LED Condition Indicators
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Doc No. 87A290 12/00
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
NO NCC
Control
Voltage
SHOWN WITHOUT
APPLIED POWER
STOP
START

INSTALLATION
Mount the Model 1732 in a stable location, observing all
precautions as outlined in the GENERAL SAFETY section
above.
The Model 1732 has 1/4” quick connect terminals for
output connections. The monitored line must be passed
through the CT access hole, located in the side of the
Model 1732. Polarity is not important.
FOR OVER-CURRENT LOAD SHUT-OFF: connect the
load control circuit to the normally closed contact. This
contact will open on over-current, breaking the load circuit.
FOR OVER-CURRENT ALARM CIRCUIT: use the
normally open contact. This will close on over-current,
sounding the alarm.
FOR UNDER-CURRENT SENSING: reverse the
contact connections as stated above (use the normally
open contact for load shutoff, or the normally closed
contact for alarm).
ADJUSTMENT
The Model 1732 is screwdriver adjustable. To adjust the
current trip level, turn the SET POINT AMPS adjustment
clockwise or counter-clockwise until the desired trip
setting is reached.
TROUBLESHOOTING
Should the Model 1732 fail to operate properly, check
that power is present, and that current flow is within the
normal operating range. Check all fuses and verify that
all wiring connections are correct. Should problems
persist, contact the manufacturer.
WARRANTY
The Model 1732 AC Current Monitor is warranted to
be free from defects in materials and workmanship for
one year. Should this device fail to operate, we will
repair or replace it for one year from the date of
purchase. For complete warranty details, see the
Terms and Conditions of Sales page in the front section
of the Time Mark catalog.
Control
Voltage
ALARM
SHOWN WITHOUT
APPLIED POWER
NO CNC
Control
Voltage
SHOWN WITHOUT
APPLIED POWER
STOP START
NO NCC
MODEL 1732 AC Current Monitor
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 1732.
ALL ELECTRICAL POWER SHOULD BE REMOVED WHEN CONNECTING OR DISCONNECTING WIRING.
THIS DEVICE SHOULD BE INSTALLED AND SERVICED BY QUALIFIED PERSONNEL.
Installation Instructions
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
E-mail: [e-mail]
Internet:http://www.time-mark.com
Doc No. 87A290 12/00
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116

SPECIFICATIONS
Model 272-24 272-120
Input Voltage 24VAC 115VAC
Input Voltage Range 20-28 VAC 100-130 VAC
Power Consumption 1.5W
VA Burden 0.5VA per phase
Frequency Range 50 -400 Hz
Current Range 1 -5 amps AC
Max. Input Current 40 amps for 2 seconds
Unbalance Adjustment 2% to 25%
Trip Delay 0.5 to 10 seconds ± 20%
Contact Rating SPDT 10A at 240VAC resistive
Expected Relay Life Mech: 10 million operations
Elec: 100,000 at rated load
Transient Protection 2500V for 10msec
Operating Temperature -40° to +131° F
Humidity Tolerance 0-97% w/o condensation
Enclosure Material ABS plastic
Weight 1 lb. 1.5 oz.
DIMENSIONS
3.0"
5.5"
3.88"
.19 dia. typ.
6.06"
2.08"
.62"
lAdjustable Trip Delay
lAdjustable Unbalance Percentage
lAutomatic Reset
MODEL 272
3-Phase Current
Unbalance Detector
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 120 VAC is required for this unit.
MAX CURRENT - MIN CURRENTMAX CURRENTMAX CURRENT
MAX CURRENTMAX CURRENTMAX CURRENT
100 = %
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Doc No. 87A135 12/00
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116

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
The Model 272 3-Phase Current Unbalance
Detector is warranted to be free from defects in
materials and workmanship for one year. Should this
device fail to operate, we will repair or replace it for one
year from the date of purchase. Contact the Time Mark
Sales department, Monday through Friday; 8 a.m. to 5
p.m., CST, for further details.
TYPICAL APPLICATION
Control
voltage
Start
Stop
AC
A B C
Motor
O/L's
MODEL 272 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
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
E-mail: [e-mail]
Internet:http://www.time-mark.com
Doc No. 87A135 12/00
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
Shows No Power Applied

DESCRIPTION
The Model 276XR Current Transmitter/Receiver
consists of two identical modules. One module accepts
the input from a standard CT, while the second module
is connected to a current monitor. The transmission
lines between the two modules can be up to 1000 feet
long.
The input module will accept any current input from zero
to 5 amps, while the output module will produce azero
to 5 amp signal. Line loss across 1000 feet is no more
than 6% of the input. The Model 276XR module will
operate with any AC current from 50 to 400 Hz. No
supply voltage is required to operate the transmitter/
receiver link.
DIMENSIONS
SPECIFICATIONS
Model 276XR
Supply voltage none required
Input current Zero to 5 amps
Output current Zero to 5 amps
Frequency range 50-400 Hz
Max. line loss 6%
In/out line 14 ga. wire
Transmission line 22 ga. wire
Transmission line length 1000 feet
Operating temperature -40° to +131° F
Humidity tolerance 0-97% w/o condensation
Mounting 8-pin socket (*order separately)
Weight (each) 4.9 oz.
*order 8-pin socket number 51X120
ll Allows longer transmission lines
from CT to current monitor
ll No external power required
ll Convenient socket mounting
ll Five year unconditional warranty
TYPICAL APPLICATION
234
5
6
7
8
1
1
2
3
4
5678
0-5 amps
0-5 amps To current monitor
From CT
Use 14 ga. Wire minimum
Keep as short as possible.
1000 ft. Using 22 ga.
CONNECTION DIAGRAM
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Doc No. 87A335 12/00
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
MODEL 276XR
Current
Transmitter/Receiver
3.25"
0.65"
1.95"
1.95"

TROUBLESHOOTING
Should these units fail to operate properly check to
make sure that all wires are connected properly to the
correct pins as shown on the front page.If problems still
persist,contact your local Distributor, or the
manufacturer at 800-862-2875.
WARRANTY
The Model 276XR Current Transmitter/Receiver is
warranted to be free from defects in materials and
workmanship, and is covered by our exclusive 5-year
Unconditional Warranty. If this device fails to
operate, for any reason, we will repair or replace it free,
for five years from the date of purchase. Contact the
Time Mark Sales department, Monday through Friday;
8 a.m. to 5 p.m. CST, for further details.
INSTALLATION
1. Place the two Model 276XR’s next to each other
with one of the models turned 180° so that it is
facing opposite the other.
2. Connect the two transmitter/receivers (CTR’s)
together using 22 gauge wire, as shown in the
diagram on the front of the page.
3. Using 14 gauge wire, connect pins 2 and 7 of one
of the CTR’s to the current transformer (CT) to be
used.
4. Connect the other CTR to your current monitor
with 14 gauge wire.
PIN CONNECTION
TYPICAL APPLICATION
234
5
6
7
8
1
1
2
3
4
5678
0-5 amps
0-5 amps To current monitor
From CT
Use 14 ga. Wire minimum
Keep as short as possible.
1000 ft. Using 22 ga.
CONNECTION DIAGRAM
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
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Internet:http://www.time-mark.com
Doc No. 87A335 12/00
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
MODEL 276XR Current Transmitter/Receiver
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 276XR.
ALL ELECTRICAL POWER SHOULD BE REMOVED WHEN CONNECTING OR DISCONNECTING WIRING.
THIS DEVICE SHOULD BE INSTALLED AND SERVICED BY QUALIFIED PERSONNEL.
Installation Instructions

DESCRIPTION
The Model 278 AC Current Transducer is designed to
accept an AC current input, and provide a proportional DC
currentoutput. A linear transformer input is coupled to a
solid-state output amplifier. The Model 278 is powered by
a 115 VAC or 230 VAC source, and is socket-mounted for
ease of use.
Model 278 Current Transducers can be used with
computer and programmable controls to provide:
-Motor and power control
-Supervisory data acquisition
-Load monitoring
-Feedback control
-Energy management
The Model 278 is available in two 4-20 output
configurations. A 0-10 VDC output is available on the
Model 2780.
ll High accuracy, low cost
ll Isolated input and output
ll Socket-mounted, solid-state design
ll Five year unconditional warranty
DIMENSIONS
3.25"
1.95"
1.95"
MODEL 278
AC Current
Transducer
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12/02
© 2002 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
MODEL C278 C278-230
Supply voltage 115VAC @ 50/60 Hz 230VAC @ 50/60 Hz
Input current 0-5 amps 0-5 amps
Input frequencies 25-400 Hz
Input burden 0.5VA at 120VAC 60 Hz
Output @ rated input 4-20ma 4-20ma
Maximum load 500 ohms 500 ohms
Output accuracy 2% at 77°F
Output ripple 1% max at nominal frequency
Response time 800 msec from 0-99%
Overload withstand 2 times rated output-continuous
10 times rated input-1 second
Dielectric withstand
voltage (isolation) 1500 VRMS input, output, case
Operating temperature -40°to +131°F
Humidity tolerance 0-97% w/o condensation
Enclosure material ABS plastic
Mounting 8-pin socket (*order separately)
Weight 9.5 oz.
Agency Approvals UL Recognized-US/Canada
*Order 8-pin socket number 51X120
SPECIFICATIONS

INSTALLATION
The Model 278 AC Current Transducer requires an 8-
pin mounting socket, such as the Time Mark Model
51X120.
The base connecting diagram on the unit shows the pin
connection numbers for the 115 volt power, the AC
Current input, and the DC Current Out.
Connect the appropriate wiring to the socket as required
(See the Typical Application diagram).
PIN DRAWING
NOTE: When installing the Model 278 Transducer in
areas of high humidity or contamination, it is
recommended that the base area and all exposed metal
parts of the socket be coated liberally with a good
quality silicon grease, such as Dow Corning DC-4 or
DC-4X. Insert the unit into the socket and wipe off
excess grease around the base. This will prevent the
entrance of moisture and other contaminates into the
base and socket areas.
TROUBLESHOOTING
Should the Model 278 AC Current Transducer fail to
operate properly, check that all voltage is present, and
is of the correct voltage level. Check all fuses and
verify that all wiring connections are correct. If
problems persist, contact your local Time Mark
Distributor, or the factory for assistance, Monday-
Friday, 8 a.m. to 5 p.m. CST.
WARRANTY
The Model 278 AC Current Transducer is warranted
to be free from defects in materials and workmanship,
and is covered by our exclusive 5-year Unconditional
Warranty. If this device fails to operate, for any
reason, we will repair or replace it free, for five years
from the date of purchase. Contact the Time Mark
Sales department, Monday through Friday; 8 a.m. to 5
p.m., CST, for further details.
AC
CURRENT
DC
CURRENT
OUT
115
VAC
1
23
4
5
6 7
8
TYPICAL APPLICATION
MODEL 278 AC Current Transducer
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 278.
ALL ELECTRICAL POWER SHOULD BE REMOVED WHEN CONNECTING OR DISCONNECTING WIRING.
THIS DEVICE SHOULD BE INSTALLED AND SERVICED BY QUALIFIED PERSONNEL.
Installation Instructions
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
E-mail: [e-mail]
Internet:http://www.time-mark.com
12/02
© 2002 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
CT-Model 276-xxx
Model 278
2 3
115
VAC DC
Current Out
1
8
6
7

MOTOR
4-20mA
OUTPUT
REVERSE WIRES TO CT
IF MOTOR FAILS TO RUN
FOR MORE THAN THE INITIAL
2 SECOND PERIOD.
MODEL 276A- xx
L1
L2
MANUAL
RESTART
120VAC
COIL
DESCRIPTION
The Model 421 Over/Under Motor Load Monitor
detects an overload or underload condition on all types
of running motors: conveyer motors, elevator motors,
mixer motors, submersible pumps, etc.
This Monitor detects the actual power used (voltage x
current xpower factor) and is more sensitive than
simple current monitors. The 421 can be used with
single phase motors or, using the Model 276C current
transducer, with three-phase motors. Matching CT’s
allow the Model 421 to be used with most motor sizes.
Optional trip and restart delays are provided.
DIMENSIONS
TYPICAL APPLICATION -single-phase monitoring
C
L
3.88"
3.0"
0.44"
3.03" Holes are symetrical
about center line.
0.203" 4 PL.
5.5" 6.06" 0.55"
2.63"
0.28"
SPECIFICATIONS
Model 421
Input Voltage Range 100-130 VAC or 200-250 VAC
Frequency 50/60 Hz
Power Consumption 0.5 VA max.
Nominal Current 2.5 amps
Minimum Current 0.25 amps
Current Adjustment 0-5 amps xPF
Current Output 4-20mA for chart recorders
Repeat Accuracy 1 % (fixed conditions)
Output SPDT 10 A at 240 VAC resistive
Expected Relay Life Mech: 10 million operations
Elec: 100,000 operations at rated load
Trip Delay OFF or 0.3 to 180 seconds
Restart Delay OFF or 0.1 to 4 hours
Indicators Red LED: Overload or Underload; tripped
Yellow LED: Restart timing
Transient Protection 2500V for 10 msec
Operating Temp -40º to 131º F
Humidity Tolerance 97% w/o condensation
Enclosure Material ABS plastic
Weight 1 lb.
Agency Approvals UL Listed to US and Canadian safety
standards CSA Certified
MODEL 421
Over/Under
Motor Load Monitor
ll Monitors True Motor Power
(volts xcurrent xpower factor)
ll Detects Motor Overload or Underload
ll Operates on 120 or 240 VAC,
Single-phase or 3-phase
ll Built-in Trip and Restart Delay Options
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Doc No. 87A182 12/00 page 1 of 8
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116

Figure 1. RESISTIVE LOAD
With a purely resistive load, the current and voltage
waveforms are occurring simultaneously.
MODEL 421 Over/Under Motor Load Monitor
READ ALL INSTRUCTIONS BEFORE INSTALLING, OPERATING OR SERVICING THIS DEVICE.
KEEP THIS DATA SHEET FOR FUTURE REFERENCE.
APPLICATION GUIDE
Figure 2. INDUCTIVE LOAD
With an inductive load, the current waveform lags the
voltage waveform by 60°.
The current, as measured with an ammeter, may only
vary a slight amount as the motor changes from a fully
loaded condition to a completely unloaded condition.
This makes it difficult to detect an unloaded condition by
simply monitoring current alone.
To obtain an accurate picture of real power
consumption of any inductive device, such as a motor,
the formula V x A x Cosø = W is used.
The Cosø is a multiplication factor derived from the
number of degrees of lag between the current and
voltage waveforms.
This is called the “power factor” (or “PF”). The power
factor is the natural cosine of the degrees of lag:
GENERAL
This application guide is written for equipment
designers, maintenance personnel, electrical
contractors, etc.
It is intended to aid in the installation of the Model 421
Motor Load Monitor into motor protection systems.
The notes and diagrams deal with methods of protecting
motors in the event of an underload condition or an
overload condition.
THEORY
The need for a system to detect an underload condition
other than by the simple monitoring of current becomes
clear when examining the following waveforms.
In a purely resistive circuit, as in Figure 1, the current
(amps) is directly proportional to the power (watts) being
consumed. To find the power, multiply the voltage
across the load times the current through the load. The
result is in watts (V x A = W).
In Figure 2, When the load is not resistive, but inductive
as it is with a motor, the formula is no longer correct.
The inaccuracy occurs because the current and the
voltage waveforms are not in phase.
The current waveform lags the voltage waveform by as
much as 90 degrees in a completely unloaded
condition, or as little as 5 or 10 degrees in a fully loaded
condition.
Degrees
of lag Power Factor Degrees of lag Power Factor
0 1.000 50 0.643
5 0.996 55 0.574
10 0.985 60 0.500
15 0.966 65 0.423
20 0.940 70 0.342
25 0.906 75 0.259
30 0.866 80 0.174
35 0.819 85 0.087
40 0.766 90 0.000
45 0.707
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Doc No. 87A182 12/00 page 2 of 8
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116

MODEL 421 Over/Under Motor Load Monitor
APPLICATION GUIDE
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
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Doc No. 87A182 12/00 page 3 of 8
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
Example: TRUE POWER CONSUMED BY AN AC
MOTOR
For this example we will use a 3-horsepower, 230 volt,
single phase motor.
Condition 1 represents the motor being used at near full
load, while Condition 2 represents a drop in motor load.
Comparing the results of this example, the motor
current decreased only 10% with a drop of 61% in the
motor load (input power). A drop in motor power
cannot be accurately measured by only monitoring the
current and voltage.
By monitoring the phase relationship and applying the
resultant power factor,an accurate and selective
method of sensing changes in true power consumption
can be obtained.
The Model 421 Monitor is based on the above principal
of detecting the actual power used, and is more
sensitive than simple current monitors.
ADDITIONAL FEATURES
As described previously, the Model 421 would fulfill the
basic requirements in most motor protection control
systems. However, there are situations which would
require the motor to restart automatically after a preset
time.
The Model 421 has an adjustable restart timer for
such applications. This timer has a range of 0.1 to 4
hours. If the restart timer is not needed, turn it off with
DIP switch 2.
If restart timing is needed for an underload condition
only, the overload restart can be turned off with DIP
switch 1.
Resetting the Model 421 is accomplished by cycling the
power off and back on, pressing the RESET button, or
by using the restart timer (DIP switch 2).
Some applications require a trip delay period before
shutting down the motor. The Model 421 has a built-in
trip delay timer. The timing range is from 0.3 to 180
seconds. The trip delay timer can be turned off with
DIP switch 4.
Refer to the chart under INSTALLATION (pg 4) for all DIP
switch settings.
Example: (V x A x Cosø = Watts)
Condition 1
230 volts x 10 amps x 0.985 pf = 2265.5 watts
Condition 2
230 volts x 9 amps x 0.423 pf = 875.6 watts
A 4-20 mA output is provided for monitoring power
consumption. A 4 mA output is equal to 0 watts and a
20 mA output is equal to 600 watts at 120 V or 1200
watts at 240 V.
This signal can be sent to a strip chart recorder, a
process controller, computer, etc.
INPUT CURRENT REQUIREMENTS
The CT input of the Model 421 is the isolated winding of
a small current transformer within the unit. Ideally, the
current range needed should be between 2 and 3.5
amps for a fully loaded motor.
Polarity of the wires connected to the CT terminals is
critical to achieve the correct phase relationship
between the current and voltage waveforms as
described earlier.
This is simple to determine after the installation is
complete (refer to the ADJUSTMENT PROCEDURE, pg
5).
If the full load motor current is 3.5 amps or less, and
the motor is a single-phase type, connect one leg of the
motor current directly into the Model 421.
Figure 3 showsthe Model 276A and Figure 4 shows
the Model 276B Current Transformers, available from
Time Mark.
Figure 3. MODEL 276A CURRENT TRANSFORMER
2.38"
1.95"
1.63" Secondary
Space for Primary turn:
0.25" 0.38"x
1.25"
0.43"
.187" dia.
Secondary terminals
(0 - 5 amps)
Loop one leg of AC
line thru transformer
as shown

276B
50 -500 600 -1200
B = 0.87”B = 0.87”
C = 1.56” C = 2.06”
3.90"
2.00"
0.44"
1.25"
4.50"
3.88"
(2) 0.27" x 0.44" slots B
C
APPLICATION GUIDE INSTALLATION INSTRUCTIONS
Figure 5. CURRENT TRANSFORMER CHART
Single-Phase 3-Phase
HP 120VAC 240VAC 240VAC 480VAC
1/4 276A-10 * *
1/3 276A-15 * *
1/2 276A-15 276A-10 **
3/4 276A-20 276A-10 **
1276A-25 276A-15 276A-10 *
1 1/2 276A-30 276A-15 276A-10 *
2276A-35 276A-20 276A-10 *
3276B-50 276A-25 276A-15 276A-10
5276B-80 276A-40 276A-25 276A-15
7 1/2 276B-150 276B-60 276A-35 276A-20
10 276B-150 276B-75 276A-40 276A-20
15 276B-60 276A-30
20 276B-80 276A-40
25 276B-100 276B-50
30 276B-150 276B-60
40 276B-150 276B-75
50 276B-200 276B-100
60 276B-250 276B-150
75 276B-300 276B-150
100 276B-400 276B-200
125 276B-250
150 276B-300
200 276B-400
250 276B-500
300 276B-600
350 276B-700
400 276B-750
500 276B-1000
* Direct connection to Model 276C (see page 8)
* * Direct connection to Model 422
MODEL 421 Over/Under Motor Load Monitor
3-PHASE INSTALLATION
The basic Model 421 Controller is designed for use with
single-phase motors. However, it can easily be used in
3-phase applications by installing the current cancelling
transformer, Model 276C. The Model 276C (figure 6)
monitors two of the three phases, and cancels the effect
of the current signal in the third phase, which would
otherwise cause a phase shift error in the Model 421.
Figure 6. MODEL 276C
IMPORTANT NOTE:
In 3-phase applications, the current inputs must
come from the same phases providing the voltage
inputs. The applications schematics shown on the
last page describe the interconnections.
INSTALLATION
Mount the Model 421 in the control panel or in a suitable
enclosure. Connect the voltage and current inputs to
the appropriate terminals on the Model 421 Monitor.
If the 4-20mA output is used, connect it across a 300Ω
resistive load. Set the four MODE switches on the
Model 421 according to the chart below. During the
initial setup you may wish to disable all time delays.
After the system is completely installed, a simple test
and adjustment will insure that the polarity and
threshold are correct.
DIP SW MODE ON OFF
1Overload Restart Disabled Enabled
2Restart Delay Enabled Disabled
3Reset Button Enabled Disabled
4Trip Delay Enabled Disabled
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Fax: [phone]
E-mail: [e-mail]
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Doc No. 87A182 12/00 page 4 of 8
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
Figure 4. MODEL 276B CURRENT TRANSFORMER
The Current Transformer Chart in Figure 5lists various
models available and is referenced to the horsepower ratings
of single-phase and 3-phase motors.
2.6"
3.6"
.187" dia. typical
4.0"
2.3"
4.6"

ADJUSTMENT
Connect a temporary jumper across the NO contacts on
the Model 421 (this keeps the motor running as the
Model 421 trips off and resets).
With the correct voltage applied to the system, the
motor should start and run continuously. Make sure the
motor is running under it’s normally loaded condition.
With a clamp-type ammeter, measure the current in one
of the wires connected to the CT terminals on the Model
421. A reading between 2 and 3.5 amps should be
measured for best results. This current level can be
changed by exchanging the CT with a different ratio.
Turn the UNDER adjustment through it’s entire range
and find the spot where the UNDERLOAD LED just
illuminates.
Turn the UNDER adjustment until the LED just goes
out. If the UNDERLOAD LED is lit all the time, reverse
the two wires connected to the CT terminals and re-
adjust.
Repeat this procedure for the OVER adjustment. If the
OVERLOAD indicator LED stays on all the time, the
current input may be incorrect. Check the CTs for
proper sizing.
Set the SECONDS adjustment for the appropriate TRIP
delay, and HOURS adjustment for the appropriate
RESTART delay, as required for the application.
Remove the jumper from the NO contacts; the motor
should continue to run. The adjustment is now
complete.
MODEL 421 Over/Under Motor Load Monitor
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 421.
ALL ELECTRICAL POWER SHOULD BE REMOVED WHEN CONNECTING OR DISCONNECTING WIRING.
THIS DEVICE SHOULD BE INSTALLED AND SERVICED BY QUALIFIED PERSONNEL.
INSTALLATION INSTRUCTIONS
TROUBLESHOOTING
Should the Model 421 Motor Load Monitor fail to
operate, check all connections to the device and its
control circuits. Insure that the proper voltage and
currents have been applied.
Check all fuses. Should the Model 421 operate
improperly, check that the CT is properly sized. Check
all DIP switch settings. If problems persist, contact the
factory for technical assistance.
OPERATION
When AC voltage is first applied, the output transfers for
approximately two seconds, completing the motor
control circuit and allowing the motor to come up to
speed.
If the power being used is within acceptable limits the
contacts remain energized and the motor continues to
run. If the power drops or rises outside the limits, the
contacts will open.
WARRANTY
The Model 421 Under/Over Motor Load Monitor is
warranted to be free from defects in materials and
workmanship for one year. Should this device fail to
operate, we will repair or replace it for one year from the
date of purchase. For complete warranty details, see
the Terms and Conditions of Sales page in the front
section of the Time Mark catalog.
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
E-mail: [e-mail]
Internet:http://www.time-mark.com
Doc No. 87A182 12/00 page 5 of 8
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116

MODEL 421 Over/Under Motor Load Monitor
TYPICAL APPLICATIONS
SINGLE-PHASE, 240V, ≥≥ 7.5 HP
THE INFORMATION PRESENTED IN THIS GUIDE IS CORRECT TO THE BEST OF OUR KNOWLEDGE. HOWEVER, TIME MARK CORPORATION
DOES NOT WARRANT THE APPLICATIONS AS OUTLINED NOR MAKE ANY OFFERS THAT THE CIRCUITS ARE FREE FROM PATENT
INFRINGEMENT. TIME MARK CORPORATION RESERVES THE RIGHT TO CHANGE OR ALTER SPECIFICATIONS AT ANY TIME.
SINGLE-PHASE, 120V, < 3 HP
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
E-mail: [e-mail]
Internet:http://www.time-mark.com
Doc No. 87A182 12/00 page 6 of 8
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
MOTOR
4-20mA
OUTPUT
REVERSE WIRES TO CT
IF MOTOR FAILS TO RUN
FOR MORE THAN THE INITIAL
2 SECOND PERIOD.
MODEL 276A-xx
L1
L2
MANUAL
RESTART
120VAC
COIL
MOTOR
4-20mA OUTPUT
REVERSE WIRES TO CT
IF MOTOR FAILS TO RUN
FOR MORE THAN THE INITIAL
2 SECOND PERIOD.
MODEL 276B-xx
L1
L2
MANUAL
RESTART
240VAC
COIL

MODEL 421 Over/Under Motor Load Monitor
TYPICAL APPLICATIONS
THE INFORMATION PRESENTED IN THIS GUIDE IS CORRECT TO THE BEST OF OUR KNOWLEDGE. HOWEVER, TIME MARK CORPORATION
DOES NOT WARRANT THE APPLICATIONS AS OUTLINED NOR MAKE ANY OFFERS THAT THE CIRCUITS ARE FREE FROM PATENT
INFRINGEMENT. TIME MARK CORPORATION RESERVES THE RIGHT TO CHANGE OR ALTER SPECIFICATIONS AT ANY TIME.
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
E-mail: [e-mail]
Internet:http://www.time-mark.com
Doc No. 87A182 12/00 page 7 of 8
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
3-PHASE, 240V, 1 to 10 HP
SINGLE-PHASE, 240V, 1/2 to 5 HP
4-20mA
OUTPUT
REVERSE WIRES
TO CT IF MOTOR
FAILS TO RUN
FOR MORE THAN
THE INITIAL
2 SECOND PERIOD.
MODEL276C
L1
L2
MANUAL
RESTART
240VAC
COIL
OBSERVE POLARITY
AS SHOWN
USE MODEL 276A-xx
MOTOR
L3
MOTOR
4-20mA OUTPUT
REVERSE WIRES TO CT
IF MOTOR FAILS TO RUN
FOR MORE THAN THE INITIAL
2 SECOND PERIOD.
L1
L2
MANUAL
RESTART
240VAC
COIL
MODEL 276A-xx

MODEL 421 Over/Under Motor Load Monitor
TYPICAL APPLICATIONS
OVER/UNDER LOAD & PHASE LOSS PROTECTION
THE INFORMATION PRESENTED IN THIS GUIDE IS CORRECT TO THE BEST OF OUR KNOWLEDGE. HOWEVER, TIME MARK CORPORATION
DOES NOT WARRANT THE APPLICATIONS AS OUTLINED NOR MAKE ANY OFFERS THAT THE CIRCUITS ARE FREE FROM PATENT
INFRINGEMENT. TIME MARK CORPORATION RESERVES THE RIGHT TO CHANGE OR ALTER SPECIFICATIONS AT ANY TIME.
3-PHASE, 240V, <1 HP
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
E-mail: [e-mail]
Internet:http://www.time-mark.com
Doc No. 87A182 12/00 page 8 of 8
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
4-20mA
OUTPUT
REVERSE WIRES
TO CT IF MOTOR
FAILS TO RUN
FOR MORE THAN
THE INITIAL
2 SECOND PERIOD.
MODEL276C
MANUAL
RESTART
120VAC
COIL
MOTOR
OBSERVE POLARITY
AS SHOWN
USE MODEL 276B-
xx
120VAC
480VAC
TIMEMARK
3-PHASEMONITOR
L1
L3
L2
4-20mA
OUTPUT
REVERSE WIRES
TO CT IF MOTOR
FAILS TO RUN
FOR MORE THAN
THE INITIAL
2 SECOND PERIOD.
MODEL276C
L1
L2
MANUAL
RESTART
240VAC
COIL
OBSERVE POLARITY
AS SHOWN
MOTOR
L3

ll Monitors 3-phase AC Current
ll Compares Three Single-phase Motors
ll Detects Open 3-phase Heating Element
ll UL Recognized; CSA Certified
DESCRIPTION
The Model 2722 Current Unbalance Detector is
designed to monitor 3-phase AC current (or compare three
single-phase AC currents). A solid-state electronic sensing
circuit drives an internal DPDT relay which energizes
during normal, balanced conditions. An unbalanced
condition will cause the relay to drop out. The formula for
an unbalance is:
The Model 2722 accepts current inputs up to 5 amps and
will consider zero amps as balanced (relay stays
energized), making the device suitable for use with 3-
phase heaters.
The Model 2722 has adjustments for percent of unbalance
and time delay before tripping. It will automatically reset
upon restoration of correct current balance, or a normally-
closed momentary switch can be connected for a manual
reset. External CT’s can be used to extend the operating
current range.
SPECIFICATIONS
Model A2722 B2722 C2722
Input Voltage 24VAC 120VAC 240VAC
Input Voltage Range 20-28 VAC 100-130 VAC 190-250 VAC
Power Consumption 1.5W max.
VA Burden 0.5VA per phase
Frequency Range 50 -400 Hz
Current Range 1 -5 amps AC
Transient Protection 2500V for 10 msec
Unbalance Adjustment 2% to 25%
Trip Delay 0.2 to 20 seconds ± 5%
Output Contacts DPDT 10A at 240 VAC resistive
Expected Relay Life Mech: 10 million operations
Elec: 100,000 at rated load
Operating Temperature -40º to +131º F
Humidity Tolerance 0-97% w/o condensation
Enclosure Material ABS plastic
Weight 1.35 lbs
Agency Approvals UL Recognized CSA Certified
DIMENSIONS
3.5"
4.5"
2.25"
3.13"
4.8"
4.0"
MODEL 2722
Current
Unbalance Detector
MAX CURRENT - MIN CURRENTMAX CURRENTMAX CURRENT
MAX CURRENTMAX CURRENTMAX CURRENT
100 = %
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
E-mail: [e-mail]
Internet:http://www.time-mark.com
Doc No. 87A150 12/00
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116

INSTALLATION
Mount the Model 2722 in a safe location, observing all
precautions as outlined in the General Safety section
above.
Connect the 3-phase wires to the terminals marked A,
B, and C. Apply power to the AC connections.
Connect the control wiring to the opposite side of the
unit, to the terminals with the relay markings. These
markings show the relays in the de-energized condition
(Refer to Typical Application diagrams).
Unbalance occurs when the amount of current
unbalance is greater than the unbalance control setting
(UNBALANCE LED-On). The unbalance condition
starts the trip delay which, after time-out, causes a
tripped condition (TRIP LED-On; relay de-energized).
The unit automatically resets when the current
unbalance is less than the unbalance setting.
An optional manual reset is also available as shown in
the Typical Application diagram. Set the UNBALANCE
and TRIPPED delays as required.
TROUBLESHOOTING
Should the Model 2722 fail to operate properly, check
that 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 [phone] for assistance.
WARRANTY
The Model 2722 Current Unbalance Detector is
warranted to be free from defects in materials and
workmanship for one year. Should this device fail to
operate, we will repair or replace it for one year from the
date of purchase. For complete warranty details, see
the Terms and Conditions of Sales page in the front
section of the Time Mark catalog.
TYPICAL APPLICATION: 3-Phase Heater
TYPICAL APPLICATION: 3-Phase Motor
Optional Manual Reset
Start
Stop
AC A B C
Reset
Motor
AC SUPPLY
to Shut-Off or Process Control Circuit
RESET
Alarm
Bell
AC SUPPLY
SCR
Proportional
Control
3-Phase
Heating Elements
AC ACB
Rst
MODEL 2722 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 2722.
ALL ELECTRICAL POWER SHOULD BE REMOVED WHEN CONNECTING OR DISCONNECTING WIRING.
THIS DEVICE SHOULD BE INSTALLED AND SERVICED BY QUALIFIED PERSONNEL.
Installation Instructions
TIME MARK is a division of
Telephone: Main -[phone]
Sales -[phone]
Fax: [phone]
E-mail: [e-mail]
Internet:http://www.time-mark.com
Doc No. 87A150 12/00
© 2000 TIME MARK CORPORATION
11440 East Pine Street
Tulsa, Oklahoma 74116
Shows No Power Applied
Shows No Power Applied