Time Mark 661 Data Sheet

MODEL 661

4-20mA

INPUT

24VDC

HIGH ALARM

LOW ALARM

TIME MARK is a division of

2.88”

2.44”

1.75”

3.52”

Alarm Control

 2 Adjustable Trip Points

 Fail-safe Operation

 Automatic Reset

 5-Year Unconditional Warranty

DESCRIPTION

The Model 661 Alarm Control, part of the 600 series line of
instrumentation controls, is designed to monitor and maintain
measurable applications such as liquid levels, temperature,
pressure, flow, etc. A user-provided 4-20mA current loop
represents the measurable application, and output connec­tions are provided for signal alarms.

Two setpoints, the HIGH ADJUST, and the LOW ADJUST, are
field adjustable. If the input is between the two setpoints, the
relays are energized. If the input is above the high setpoint,
the HIGH ALARM relay de-energizes to provide a tripped
condition. This tripped condition will automatically reset when
the input falls back below the setpoint. If the input falls below
the low setpoint the LOW ALARM relay de-energizes. The
tripped condition resets when the input rises back above the
setpoint.

The Model 661 is equipped with top-mounted LEDs for trip
status indication. A HIGH ALARM or LOW ALARM LED turns
OFF in a tripped condition. The INPUT LOOP ERROR LED
turns ON if the input is outside the 4-20mA range.

A Time Mark Model 650 Loop Power Supply (or equivalent)
is required to provide DC operating voltage. A Time Mark
Model 672-15 Pressure Transducer (or equivalent) is
required to provide the input signal.

SPECIFICATIONS

Model 661

Operating Voltage 24VDC ±5%

Supply Current 30mA maximum

Input Signal 4-20mA

Input Resistance 50 ohms

Input Loop Error High: 23-25mA

Trip Adjustment

Hysteresis

Contact 10 amps at 240VAC resistive

Operating
Temperature

Expected Relay Life

Humidity Tolerance 0-97% w/o condensation

Enclosure Material ABS plastic

Weight 6 oz.

Mounting 11-pin socket (*order separately)

Low: 2-3mA

High: 4-20mA
Low: 4-20mA

2.5% at midrange

-13º to +122º F

Mech: 10 million operations
Elec: 100,000 at rated load

* Order 11-pin socket number 51X016

DIMENSIONS

PIN DIAGRAM

01/2012

© 2012 TIME MARK CORPORATION

MODEL 661

TIME MARK is a division of

Alarm Control

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

KEEP THIS DATA SHEET FOR FUTURE REFERENCE.

GENERAL SAFETY

THE MODEL 661 ALARM CONTROL IS NOT TO BE USED WITH INPUT VOLTAGES OTHER THAN 24VDC. ALL

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

DEVICE AND WIRING SHOULD BE INSTALLED AND SERVICED BY QUALIFIED PERSONNEL.

Installation Instructions

INSTALLATION

Connect 24 VDC power to pins 1 and 3 on the 11-pin socket.

Connect the 4-20mA input signal to pins 4 and 5, and the
other pins to the appropriate units in your loop system
following the base diagram shown on the Model 661 device
(and on this data sheet). Pay careful attention to polarity.

NOTE: When installing the Model 661 Control 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 pre-vent
the entrance of moisture and other contaminates into the base
and socket areas.

ADJUSTMENT

The Model 661 Alarm Control relays are normally energized
when the input is between the trip points. If the input rises
above the HIGH trip point, or falls below the LOW trip point,
the high or low alarm relay de-energizes. Either way, the
relay returns to the energized state when the input signal is
again between the two setpoints (see the Operation Diagram).
The HIGH ALARM and LOW ALARM LEDs may be used to
indicate the tripped condition in the following adjustments.

Before Adjustment: For each application, you must select
the HIGH ALARM and LOW ALARM setpoints. These two
setpoints, in milliamps, are used to adjust the Model 661.

To Begin: Turn the LOW ADJUST fully counter-clockwise, to

it’s lowest setting, then turn the HIGH ADJUST fully clockwise
to it’s highest setting. Both ALARM LED’s should be lit.

To adjust the HIGH ALARM: With the Model 680 4-20mA
Simulator (or other adjustable, known signal source), apply

the current level for the HIGH ALARM. Turn the HIGH
ADJUST pot slowly, counter-clockwise until the HIGH ALARM
LED goes out.

To Adjust the Low Alarm: With the Model 680 4-20mA
Simulator (or other adjustable, known signal source), apply
the current level for the LOW ALARM. Turn the LOW
ADJUST pot slowly, clockwise until the LOW ALARM LED
goes out.

Check Setpoints: With the Model 680 4-20mA Simulator
(or other adjustable, known signal source), check the high
and low alarm setpoints by applying current levels above and
below the chosen setpoints, noting the current values shown
when the LEDs come on.

Input Loop Error: Check the INPUT LOOP ERROR function
by applying current levels above and below the 4-20mA
range. The INPUT LOOP ERROR LED should illuminate
when current is above 20mA or below 4mA.

OPERATION DIAGRAM

WARRANTY

This product is warranted to be free from defects in mate­rials and workmanship, and is covered by our exclusive 5­year 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.

01/2012

© 2012 TIME MARK CORPORATION