Kooltronic Guardian K3NA4C3DP24L User manual

Keep This Manual
With Air Conditioner
AIR CONDITIONER
OPERATOR'S MANUAL
CAUTION
BEFORE INSTALLING AND
USING THIS AIR CONDITIONER,
IT IS IMPORTANT THAT THIS
MANUAL BE READ AND
UNDERSTOOD THOROUGHLY
KOOLTRONIC, INC.
30 Pennington-Hopewell Road
Pennington, NJ 08534
609•466-3400
FAX: 609 • 466-1114
www.kooltronic.com
900-039-73 (10/21)
(CDR: 20368)
GUARDIAN SERIES
K3NA4C3DP24L
480 Volt 1-PHASE
Find additional information on
this model at kooltronic.com or
use the Technical Documents
QR code below.
Technical
Documents

TABLE OF CONTENTS
Page
I. Introduction 2
II. Incoming Inspection 3
III. Product Handling 3
IV. Product Identification and Nameplate 4
V. Principles of Operation 5 - 8
VI. Pre-Installation Testing 9
VII. Specific Model Data 10 - 13
Mounting
Drawings and Dimensions
Technical Data
Major Component Replacements
Standard Features
VIII. Maintenance 14 - 15
IX. Trouble Shooting 15 - 16
X. Warranty 17
NOTE: Wiring Schematics are available on the specific model page of the Kooltronic website.
I. Introduction
Kooltronic Air Conditioners are designed to provide a cool, dehumidified environment for your electronic
components. There are models to fit virtually all sizes and shapes of electronics enclosures, in
capacities ranging from 1,000 to 30,000 BTU/H. Our "closed-loop" design also ensures that your
components will not be exposed to hot, dirty operating conditions.
This Manual provides you with the necessary general information for properly installing and operating
standard Kooltronic Air Conditioners. Technical data and mounting instructions are presented on pages
10 through 13.
2

3
II. Incoming Inspection
Kooltronic Air Conditioners are designed, built and packaged to withstand the shock and vibration normally
associated with shipment by common carriers. Occasionally improper handling during shipping causes damage.
Such handling could include unbanding of palletized shipments, failing to respect "This Side Up" arrows, rough
handling, falling off conveyors, excessive vibration, crushing, etc. Therefore, a thorough inspection should be
done upon receipt of all shipments. Any carton tears, dents, scratches, loose articles or evidence of oil are signs
of damage and should be noted on the Freight Bill. Cartons should be opened promptly and the units inspected
for CONCEALED DAMAGE. Kooltronic Air Conditioners must be delivered in the proper mounting position to
assure that damage to the compressor has not occurred during shipping. Any Kooltronic Air Conditioner that is
delivered removed from the banded pallet, lying down or double stacked should be refused.
An immediate claim MUST be filed with the freight carrier and an inspection requested. Retain all packing
materials. Kooltronic cannot assume responsibility for Consignee's failure to file a timely freight claim.
III. Product Handling:
1) Do not attempt to operate your Kooltronic Air Conditioner until you read and thoroughly understand this
Manual. See section VI PRE-INSTALLATION TESTING.
2) Before operating the Kooltronic Air Conditioner be certain that it is placed in its correct mounting position.
This Air Conditioner is designed to operate in a vertical position only. This placement must be done
a minimum of 5 minutes prior to operating in order to allow the compressor oil to drain to the compressor
sump area.
CAUTION
3) Before operating this unit, all electrical wiring must be checked to assure the proper connection to the
correct power source. Minimum circuit ampacity should be at least 125% of the amperage found on the
nameplate for the corresponding voltage. Do not exceed the maximum fuse size found on the nameplate.
4) We do not recommend that Air Conditioners be shipped to their final destination attached to an enclosure.
In the event that the Air Conditioner needs to be shipped attached to an enclosure it is strongly
recommended that proper support be provided for the Air Conditioner. Excessive vibration can occur if Air
Conditioners are not properly supported when shipped on enclosures, increasing the potential for internal
damage and voiding the warranty.
5) PROCEDURE FOR PROPER PACKING AND SHIPMENT OF KOOLTRONIC AIR
CONDITIONERS:
■Keep Air Conditioner in proper upright position indicated by arrow markers.
■Pack Air Conditioner in an appropriate carton (preferably original carton if possible), with
adequate internal protective packaging, making sure carton is marked and is kept in correct
upright position.
■For local, controlled transportation, strap carton to a secure part of truck to prevent falling or
sliding, minimize vibration, etc.
■For common carrier shipment, band unit(s) securely to a pallet. Unpalleted shipment risks
severe damage which voids the warranty.
Kooltronic Air Conditioners must be operated in their proper mounting position. If attempts are
made to operate a unit that is not in its designed mounting position, permanent compressor
damage will occur. This action will void the warranty. To avoid compressor damage do not tip the
unit more than 45° from its proper mounting position.

4
IV. Product Identification and Nameplate
Each Kooltronic Air Conditioner includes an identification nameplate. This nameplate provides:
qModel Number
wSerial Number
eElectrical power characteristics
rMaximum and minimum ambient operating temperatures
tCooling capacity
yType and amount of refrigerant required for recharging
uDesign Pressure
iMaximum Fuse Size
oManufacturing Order Number
aFilter Part Number
sUnderwriters Laboratories Inc. Listed or Recognized Marks and NEMA ratings
We recommend you copy this information from your unit.
qwo When ordering parts, specify the Model Number, Serial Number & MFG. Order Number.
eBefore operating, be sure that the power source matches these requirements.
yUse of incorrect type or amount of refrigerant will adversely affect performance and may damage the unit.
r Make sure that these parameters are met. Failure to do so may result in permanent damage to the unit.
ALL MOTORS ARE THERMALLY PROTECTED
VIOLATES WARRANTY
UNAUTHORIZED SERVICE OR MODIFICATION
OUTDOOR USE
COMPARTMENT ONLY
NEMA/EEMAC/UL50 BY UNDERWRITERS LABORATORIES, INC.
TYPE 1 SPECIAL PURPOSE AIR CONDITIONER EQUIPMENT
TYPE 3R, 12 & 4 INTERFACE TO THE ELECTRICAL ENCLOSURE ONLY
NEMA/EEMAC/UL50 BY UNDERWRITERS LABORATORIES, INC.
SPECIAL PURPOSE AIR CONDITIONER
FUSE SIZE
MAX.
HIGHLOW
Oz.REFRIGERANT
MAX.°FMIN.°F
AMBIENT TEMP.COOLING
ALLOW 5 MIN. BEFORE RESTARTING AFTER SHUTDOWN
Air Conditioner
DESIGN PRESSURE P.S.I.G.
MFG. ORDER NO.
KOOLTRONIC, INC. PENNINGTON, NJ
MANUFACTURED BY:
COOLING BTU
F.L.A.PH.FREQ.
VOLTS
SERIAL NUMBERMODEL NUMBER
FILTER P/N
qw
eeee rr
ty
uu i
o
as
LISTED 84H7
SPECIAL PURPOSE
AIR CONDITIONER

5
V. Principles of Operation
Kooltronic Air Conditioners are required when the equipment operating
temperature must be kept near or lower than the ambient room temperature,
and/or the cabinet must be sealed from dust, fumes, oil, corrosives and other
contaminants. These Air Conditioners utilize a "Closed-Loop Cooling System" to
ensure optimum performance of the installed components.
Closed-Loop cooling seals the electronic enclosure from hostile elements in the
environment. Two separate circulation systems are employed. The internal system
cools and dehumidifies the air inside the cabinet, totally isolating the sensitive
electronics and other components from the environment. The external system
uses circulating ambient air or water to discharge the heat removed from the
electronics. The heat is dissipated from the enclosure by means of the vapor
compression refrigeration cycle. This takes place in a hermetically-sealed
refrigeration system, utilizing either an air-cooled or water-cooled condenser heat
exchanger. The warm air inside the enclosure is drawn through the evaporator coil
where it is cooled, dehumidified and returned.
Any enclosure moisture accumulated on the evaporator coil is collected in the
condensate tray and removed through the drain tube to the condensate evaporator. Condensate evaporates in the
condensate evaporator and is released to the ambient air by the condenser impeller.
The heat removed through the evaporator coil is transferred by the compressed refrigerant to the condenser coil. Ambient
air is then passed through the condenser coil, where it absorbs the heat and is then discharged to the environment.
When the Kooltronic Air Conditioner is properly sized it should operate constantly and maintain 75°F to 115°F enclosure
temperature, depending on the ambient temperatures.
UNITS EQUIPPED WITH PROGRAMMABLE THERMOSTAT
For units equipped with Low Temperature Thermostat, see page 8.
CONTROL ACTION
The evaporator blower operates continuously. The compressor is cycled on
and off by the action from the factory preset programmable thermostat. A
pressure switch controls the on/off action of the condenser blower.
The regulation is performed according to the temperature measured by the
thermostat probe with a positive differential from the set point: if the
temperature increases and reaches set point plus differential the compressor
is started and then turned off when the temperature reaches the set point
value again.
In case of fault in the thermostat probe the start and stop of the compressor
are timed through preset parameters.
The programmable thermostat is located as shown in the upper right ISO illustration. WARNING: the programmable device
is preprogrammed and set at the factory. In the event changes are needed the following instructions can be used.
FRONT PANEL COMMANDS
FRONT PANEL LED INDICATORS
- To display target set point; in programming mode it selects a parameter or confirms an operation.
(UP) - To see the max. stored temperature; in programming mode it browses the parameter codes or increases the displayed value.
(DOWN) - To see the min. stored temperature; in programming mode it browses the parameter codes or decreases the displayed value.
- To switch the instrument off, if onF = oFF.
- Not enabled.
(DEF) - To start a manual defrost.
KEY COMBINATIONS
To lock and unlock the keyboard.
To return to the room temperature display.
To enter programming mode.
CONDENSER
AIR OUT
SUPPLY
AIR OUT
RETURN
AIR IN
CONDENSER
AIR INLET
PROGRAMMABLE
THERMOSTAT
NEMA DP24L

Principles of Operation (con’t)
MAX AND MIN TEMPERATURE MEMORIZATION
HOW TO SEE THE MIN TEMPERATURE:
1) Press and release the down arrow key.
2) The “Lo” message will be displayed followed
by the minimum temperature recorded.
3) Press the down arrow key again or wait 5 seconds
to restore normal display.
HOW TO SEE THE MAX TEMPERATURE:
1) Press and release the up arrow key.
2) The “Hi” message will be displayed followed
by the maximum temperature recorded.
3) Press the up arrow key again or wait 5 seconds to
restore normal display.
HOW TO RESET THE MAX AND MIN TEMPERATURE
RECORDED:
1) Press the SET key for more than 3 seconds while the
max or min temperature is displayed. (rSt message
will be displayed.)
2) To confirm the operation, the “rSt” message starts
blinking and the normal temperature will be displayed.
MAIN FUNCTIONS
HOW TO SEE THE SETPOINT:
1) Press and immediately release the SET key.
The display will show the set point value.
2) Press and immediately release the SET key, or
wait 5 seconds to display the probe value again.
HOW TO CHANGE THE SETPOINT:
NOTE: The standard set point is 75°.
1) Press the SET key for more than 2 seconds to
change the set point value.
2) The value of the set point will be displayed and
the °C or °F LED starts blinking.
3) To change the set value push the up or down
arrow keys within 10 seconds.
4) To store the new set point value push the SET
key again, or wait 10 seconds.
HOW TO CHANGE A PARAMETER VALUE:
To change a parameter’s value, operate as follows:
1) Enter the Programming mode by pressing the
SET plus down arrow keys for 3 seconds (the
°C or °F LED starts blinking).
6
2) Select the required parameter. Press the SET
key to display its value.
3) Use up or down arrow keys to change its value.
4) Press SET to store the new value and move to
the following parameter. To exit, press SET and
the up arrow keys or wait 15 seconds without
pressing a key.
NOTE: The set value is stored even when the
procedure is exited by waiting for the time-out
to expire.
HOW TO LOCK THE KEYBOARD:
1) Press and hold the up and down arrow keys
simultaneously for more than 3 seconds.
2) The POF message will be displayed, and the
keyboard will be locked. At this point, it will only
be possible to see the set point or the MAX or
MIN temperature stored.
3) If a key is pressed more than 3 seconds, the
POF message will be displayed.
HOW TO UNLOCK THE KEYBOARD:
1) Press and hold the up and down arrow keys
simultaneously for more than 3 seconds until
the Pon message is displayed.
OPTIONAL MONITORING SYSTEM
TTL SERIAL LINE - FOR OPTIONAL MONITORING
SYSTEMS:
The optional TTL serial line, available through the
HOT KEY connector, allows through the use of
the external TTL/RS485 converter, connection of
this digital converter to a monitoring system that is
ModBUS-RTU compatible (X-WEB500/3000/300).
Connections are provided through an external 2-
position terminal block.

Principles of Operation (con’t)
RESETTING
If it becomes necessary to reset the unit, the factory settings are as follows:
7
PARAMETER DESCRIPTION VALUE UNIT RANGE
MINIMUM MAXIMUM
SEt Set Point 75 °F 60 95
Hy Differential 10 °F 1 45
dP4 Fourth probe display 0 -- -- --
dP3 Third probe display 0 -- -- --
dP2 Evaporator probe display 0 -- -- --
dP1 Room probe display 0 -- -- --
AFH Differential for temperature alarm recovery 2 °F 1 45
ALL Minimum temperature alarm 35 °F -67 120
ALU Maximum temperature alarm 120 °F 35 302
SHy Differential for auxiliary relay 5 °F 1 45
SAA Set point for auxiliary relay 115 °F -67 302
ACH Kind of action for auxiliary relay CL -- -- --
AC Anti-short cycle delay 2 min 0 50
odS Outputs delay at start up 0 min 0 255
P2P Evaporator probe presence n -- -- --
ot Thermostat probe calibration 0 °F -21 21
US Maximum set point 95 °F 75 302
LS Minimum set point 60 °F -67 75
Ptb Map code 7 -- 0 65535
rEL Software release 0 -- -- --
rSE Real set point 0 -- -- --
onF on/off key enabling ES -- -- --
PbC Kind of probe ntc -- -- --
Adr Serial address 1 -- 1 247
HES Differential for energy saving 0 °F -54 54
rrd Regulation restart with door open alarm y -- -- --
odc Compress status when open door no -- -- --
nPS Number of activation of pressure switch 15 -- 0 15
did Digital input alarm delay 5 min 0 255
i1F Digital input configuration EAL -- -- --
i1P Digital input polarity cL -- -- --
dAO Delay of temperature alarm at startup 00:00 h -- --
ALd Temperature alarm delay 0 min 0 255
ALc Temperature alarms configuration Ab -- -- --
ArP Probe selection for auxiliary alarm P1 -- -- --
dLy Display temperature alarm 00:00 min. 0 20
Lod Probe displayed P1 -- -- --
rES Resolution in -- -- --
CF Temperature measurement unit F -- -- --
CH Kind of action: heating cooling cL -- -- --
COF Compressor OFF time with faulty probe 4 min 0 255
COn Compressor ON time with faulty probe 20 min 0 255
O4 Fourth probe calibration 0 °F -21 21
P4P Fourth probe presence n -- -- --
O3 Third probe calibration 0 °F -21 21
P3P Third probe presence n -- -- --
OE Evaporator probe calibration 0 °F -21 21

8
Principles of Operation (con’t)
UNITS EQUIPPED WITH LOW TEMPERATURE THERMOSTAT
A Low Temperature Thermostat prevents the evaporator coil from
freezing. In conditions of low ambient temperature and low enclosure
load, the thermostat regulates the return air temperature from 75°F to
86°F. The standard set point of the Low Temperature Thermostat is
75°F. The set point can be changed to 70°F or to 79°F by changing
the location of the thermostat jumper (See illustrations on page 11).
The Low Temperature Thermostat has a test start relay. When the air
conditioner is turned on it will run constantly for the first 15 minutes
regardless of external temperatures. Afterwards, if the entering
evaporator air temperature is lower than the thermostat set point, the
compressor and condenser blower will stop, and the thermostat will begin
to control the air conditioner.
The heater kit consists of a heater, a heat control thermostat and a heater
limiter. The heater control thermostat is a bimetal disk with a fixed set
point of 60°F. When the entering evaporator air temperature rises above
60°F the heater shuts off, and when the evaporator air temperature falls
below 40°F the heater will engage. The contact points of the alarm
thermostat are normally closed. If the entering evaporator air temperature exceeds 130°F the alarm thermostat
contacts open, and when the temperature drops below 130°F the contacts close.
A condenser fan speed controller is standard on this unit. The speed controller temperature sensor is installed in
the refrigerant liquid line. When the ambient temperature is above 95°F the condenser fan will run at full speed.
When the ambient temperature is between 85°F and 95°F the condenser fan will run between maximum and
minimum speed. When the ambient temperature is lower than 85°F the condenser fan will cycle. In applications
having frequent voluntary heat load fluctuations, an optional Compressor Short Cycle Protector is recommended.
When the Kooltronic Air Conditioner is properly sized it should operate constantly and maintain 75°F to 115°F
enclosure temperature, depending on the ambient temperatures.
CONDENSER
AIR OUT
SUPPLY
AIR OUT
RETURN
AIR IN
CONDENSER
AIR IN
NEMA DP24L

VI. Pre-Installation Testing
Before mounting the air conditioner to the enclosure, test for proper operation. This will verify the shipping integrity
of the system. Please follow the steps below prior to installation.
CAUTION
1. The unit must sit in an upright position at a minimum room temperature of 65°F to allow the system to warm-
up. This is particularly important during winter months.
2. Refer to the nameplate for proper electrical voltage and current requirements. Connect the power cord to a
properly grounded and fused electrical supply, leaving electrical power to the unit turned off.
3. Turn the electrical power on.
4. Verify that the evaporator blower or fan is running.
5. Observe the temperature on the digital display. The thermostat must be set a minimum of 10°F below this
temperature for the compressor to operate (the factory setting is 75°F). Refer to page 6 for instructions on
adjustment of the thermostat.
6. Operate the air conditioner for approximately ten (10) minutes. During this period the evaporator fan should
operate continuously and no unusual noise or vibration should be evident. The condenser blower is
controlled by a pressure switch and may not start for several minutes. Depending on ambient conditions, the
condenser blower may cycle during the test. The cool air discharged should be less than 70°F when the
room temperature is between 70°F and 80°F. It is normal for the condenser blower to cycle on/off during this
period.
7. Reset the thermostat to the factory setting. WARNING: Operating the unit below 75°F may result in
freezing of the evaporator coil.
8. Turn off the electrical power and disconnect the air conditioner from the power source.
NOTE: Before shipment all Kooltronic Air Conditioners are subjected to a performance test.
9
The air conditioner must be standing in its proper mounting position for a minimum of five
(5) minutes prior to testing. Failure to follow this procedure will cause permanent damage to
the compressor. To avoid compressor damage do not tip the unit more than 45° from its
proper mounting position.

10
If the air conditioner is mounted to the cabinet door you must be sure that the door hinges
will support the additional weight of the air conditioner. Also be certain that when the door
is opened fully, the cabinet does not become unbalanced. The actual weight of the unit can
be found in the Technical Data on page 13.
VII. Specific Model Data
Mounting
Kooltronic Air Conditioners have been engineered to be installed easily. To avoid damaging your Air
Conditioner, please read the following information before installation.
•Refer to page 11 for the location of all mounting holes and cutouts.
•Make sure the cutouts don't interfere with components inside your cabinet.
•Proper alignment of all air inlets and outlets is essential for optimum performance of the air
conditioner.
•All externally-mounted air conditioners are fully gasketed to ensure proper sealing. This seal is
necessary to maintain the integrity of the closed-loop system.
•Use all existing mounting holes to insure stability and a tight seal.
•Attach the supplied drain hose to the drain exit on the lower side panel of the air conditioner.
•The external drain hose must not be elevated above the exit port. Improper mounting will impede the
flow of condensate and may cause internal malfunctions.
CAUTION