User Guide

Probe Probe
12 VDC 12 VDC
Common
Normally Open
Normally Closed
SW2
Common
Probe Probe
12 VDC 12 VDC
Common
Normally Open
Normally Closed
SW2
SW2
APPLICATION
A refrigerator or freezer maintains its temperature by
periodically cycling a compressor and fan(s) on and off as
controlled by the thermostat in the cooled compartment.
As a result of this on-off type of control, the compartment
temperature will normally vary 3-5 degrees around the point
set by the compartment thermostat. In addition to this
variation, a frost-free freezer compartment will have 1 to 4
defrost cycles during a 24-hour period. This will cause the
compartment temperature to rise above the normal
variation.
The TA2 Temperature Alarm is a single point or threshold
type of temperature alarm. This type of temperature alarm
monitors the temperature at the sensor probe tip and when
this temperature passes above (or below) the set point, the
unit will execute a preset operation. In the case of the TA2,
this will be to sound an audible alarm, close a set of relay
contacts and flash a front panel LED. A user selectable one
hour delay will prevent false alarms in freezers caused by
defrost cycles and frequent door openings.
INSTALLATION
The TA2 may be mounted to any flat surface, in any position, using the two holes provided at the top of
the case or with the supplied adhesive pads. Avoid mounting in areas of excessive humidity or
temperatures outside the operating range of the TA2.
SENSOR EXTENSION
The TA2 sensor probe is designed to measure air temperature and may be mounted in any convenient
location in the area to be monitored. The sensor probe may be extended up to 200 feet with any 24AWG
stranded wire.
RELAY CONTACTS
The TA2 may be connected to a remote alarm using the relay contacts provided under the Switch Cover.
Connections are provided for Normally Open or Normally Closed Dry Contacts. Dry Contacts mean that
no electrical power is supplied to the contacts and power for a remote alarm or other device must be
supplied externally. When an alarm occurs the N.O. relay contacts will close and remain closed as long
as the alarm condition exists.
OPERATION
Plug the TA2 into a 120VAC (220V available) outlet and verify that the POWER “ON” light is illuminated.
If this light is not on, the TA2 is not receiving power and is not operating. For continued protection, this
requires immediate attention.
Set the Front Panel Adjustment for the temperature the TA2 must respond to. Typical values will be
between 35 to 45 degrees for a refrigerator and 0 to 15 degrees for a freezer. The setting of this
adjustment will depend on the type of protection the TA2 is being used for and it is up to the judgement of
the user to select an appropriate alarm temperature.
The TA2 is set at the factory to Alarm on a RISE above the temperature set on the Front Panel
Adjustment, after a one-hour delay. The UP/DOWN Switch is in the UP position and the DELAY/NO
DELAY switch is set to the DELAY position.
Remove the Switch Cover and locate SW1, the slide switch on the left-hand side. Note the lettering
underneath this switch (DOWN-UP). Setting this switch to UP will cause the alarm to be activated when
the sensor temperature rises ABOVE the temperature set on the front panel. Setting this switch to DOWN
will cause the alarm to activate when the sensor temperature falls BELOW the temperature set on the
front panel.
TYPICAL CONNECTIONS ARE SHOWN IN THE DRAWING
Locate SW2, the switch on the right hand side. Note the lettering underneath this switch (DELAY – NO
DELAY). Setting this switch to DELAY will cause the TA2 to blink the ALERT Light when the Sensor
temperature passes the threshold set by the Front Panel Adjustment. When approximately one hour has
passed and the Sensor temperature has remained past the threshold set by the Front Panel Adjustment,
the TA2 will sound the audible alarm and close the N.O. relay contacts. Should the temperature return to
its normal value before this period has elapsed, the one-hour delay will be reset. Setting this switch to
NO DELAY will cause the TA2 to sound an immediate alarm and blink the ALERT light when the
temperature passes the threshold set by the Front Panel Adjustment. Should the temperature return to its
normal value, the TA2 will automatically reset.
Locate the terminal strip below SW1 and SW2. This is where the power supply, sensor probe, and
remote alarm are connected to the TA2. The TA2 comes from the factory with the power supply and
sensor probe attached. Note the lettering for terminals 5, 6 and 7. These are the relay contacts for use
with external devices, such as remote alarms or automatic dialers. Since each installation has different
requirements, it is suggested you consult the instructions supplied with any remote device prior to
making any connections to the TA2. Note the 5 Amp 120VAC rating of the relay contacts. PERMANENT
DAMAGE will result if these limits are exceeded.
TA2 WARRANTY
LIMITED TO ONE YEAR FROM DATE OF PURCHASE
Sealed Unit Parts Co., Inc. warrants its products to be free from defects in materials and workmanship
under normal use and service. Sealed Unit Parts Co., Inc. will repair or replace without charge any such
products it finds to be so defective on its return to Sealed Unit Parts Co., Inc. The foregoing is in lieu of
all other expressed or implied warranties, including those of merchantability or fitness for a particular
purpose. The foregoing is also the purchaser’s sole remedy and is in lieu of all other guarantees,
obligations or liabilities or any consequential or incidental damages attributable to negligence or strict
liability.
SPECIFICATIONS
Power
Probe Precision sensor with 6-foot cord (20540)
Alarm Adjustment Range -10°F to +80°F
Remote Connections Screw Type 120VAC 5 Amp Max.
Operating Temperature Range +32°F to +130°F
Storage Temperature Range 0°F to +160°F
Mounting Flat Surface, External Holes Provided
Dimensions 3” x 4 7/8” x 1 5/8”
Case Material Hi Impact Thermoplastic
Adapter 120 VAC 12 VDC with 6 ft.
cable included (220V available)
NO
N.C
Power
Supply
Normally Open