nvent SPECTRACOOL G28 User manual

© 2018 nVent 89145707
Rev. C P/N 89145707
SPECTRACOOL
Air Conditioner
G28 Model 400/460V 3-PhAse
INSTRUCTION MANUAL

© 2018 nVent 89145707
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WARRANTY AND RETURN POLICY
Visit https://hoffman.nvent.com/en/hoffman/warranty-information for Product warranty and return policy.
TABLE OF CONTENTS
WARRANTY AND RETURN POLICY................................................................................................................................................2
RECEIVING THE AIR CONDITIONER...............................................................................................................................................3
HOW TO READ MODEL NUMBERS.................................................................................................................................................3
HANDLING AND TESTING THE AIR CONDITIONER......................................................................................................................3
Installation Instructions...................................................................................................................................................................4
Table 1 - Airow Clearance (inches) .............................................................................................................................................................4
Table 2 - Service Clearance (inches).............................................................................................................................................................4
OPERATING THE AIR CONDITIONER .............................................................................................................................................7
GENERAL.........................................................................................................................................................................................................7
DIGITAL DISPLAY............................................................................................................................................................................................7
Table 3 - Home Screen Symbols ...................................................................................................................................................................8
Interacting with the Digital Display................................................................................................................................................................8
Main Menu choices ........................................................................................................................................................................................9
User Interface menu choices.........................................................................................................................................................................9
System Interface menu choices....................................................................................................................................................................9
System settings menu choices .....................................................................................................................................................................9
Table 4 - Control parameters and settings .................................................................................................................................................10
CONTROLLER PARAMETERS....................................................................................................................................................... 11
Cooling Set-Point ..........................................................................................................................................................................................11
Differential +/- ...............................................................................................................................................................................................11
Table 5 - Differential......................................................................................................................................................................................11
Cooling Differential.......................................................................................................................................................................................11
Table 6 - Cooling Differential........................................................................................................................................................................11
Temperature Scale........................................................................................................................................................................................11
CONTROLLER FEATURES............................................................................................................................................................. 12
Automatic Phase Correction .......................................................................................................................................................................12
Random Start ................................................................................................................................................................................................12
Enclosure Fan Control ..................................................................................................................................................................................12
Condenser Fan Control (HPC) .....................................................................................................................................................................12
Pressure Malfunction Alarm (MALF) ..........................................................................................................................................................12
Condenser Coil Temperature Sensor..........................................................................................................................................................12
Compressor Restart Time Delay .................................................................................................................................................................12
Door Switch (Optional).................................................................................................................................................................................12
Alarm Relay Output (Optional).....................................................................................................................................................................12
Display Alarm Status ....................................................................................................................................................................................12
High Temp Shutdown...................................................................................................................................................................................12
Evaporator Coil Freeze Protection (Optional).............................................................................................................................................12
Table 7 - Alarm Condition Display ...............................................................................................................................................................13
Remote Access Control ...............................................................................................................................................................................13
MAINTENANCE............................................................................................................................................................................. 15
Compressor...................................................................................................................................................................................................15
Inlet Air Filter .................................................................................................................................................................................................15
How To Remove, Clean or Install a New Inlet Air Filter .............................................................................................................................15
Condenser and Evaporator Air Movers.......................................................................................................................................................15
Refrigerant Loss............................................................................................................................................................................................16
Table 8 - Refrigerant Properties Chart (R 134a).........................................................................................................................................16
Table 9 - Functional Data .............................................................................................................................................................................16
Table 10 - Unit Characteristics.....................................................................................................................................................................17
SERVICE DATA .............................................................................................................................................................................. 18
Table 11 - Components List.........................................................................................................................................................................18

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RECEIVING THE AIR CONDITIONER
Inspect the air conditioner. Check for concealed damage that may have occurred during shipment. Look for dents,
scratches, loose assemblies, evidence of oil, etc. Damage evident upon receipt should be noted on the freight bill.
Damage should be brought to the attention of the delivering carrier -- NOT to nVent Equipment Protection -- within
15 days of delivery. Save the carton and packing material and request an inspection. Then le a claim with the
delivering carrier.
nVent Equipment Protection cannot accept responsibility for freight damages; however, we will assist you in any
way possible.
HOW TO READ MODEL NUMBERS
G28 06 4 6 G050
12345
1. G28 identies the type/family of air conditioner and the approximate height (i.e. G28 = Global
family about 28 inch high).
2. 06 = the air conditioner’s listed capacity in BTU/Hr. at rated conditions. (i.e. 06 = 6,000 BTU/Hr. at
131/131 F)
3. 4 = 460 Volt.
4. 6 = 50/60 Hz or 60 Hz only.
5. G050 = Unique set of numbers for each air conditioner which identies the accessories on a
model.
HANDLING AND TESTING THE AIR CONDITIONER
If the air conditioner has been in a horizontal position, be certain it is placed in an upright, vertical or mounting
position for a minimum of ve (5) minutes before operating.
Do not attempt to operate the air conditioner while it is horizontal
or on its side, back or front. The refrigeration compressor is lled
with lubricating oil. This will cause permanent damage to the air
conditioner and also voids the warranty.
CAUTION
TEST FOR FUNCTIONALITY BEFORE MOUNTING THE AIR CONDITIONER TO THE ENCLOSURE.
We recommend that you test the air conditioner in cooling mode for functionality before mounting on the
enclosure. Refer to the nameplate for electrical current requirements, and wire the unit to a properly grounded
power supply using copper conductors only. Restrain the power supply wiring to ensure no contact with internal
fan. Minimum circuit ampacity should be at least 125% of the amperage shown on the unit nameplate. No other
equipment should be connected to this circuit to prevent overloading.
Apply power to the air conditioner. The cooling set-point must be below the ambient temperature to initiate
cooling mode. Refer to OPERATING THE AIR CONDITIONER on page 7 to adjust the cooling set-point. Operate
the air conditioner in cooling mode with the compressor running for ve (5) to ten (10) minutes. Very quickly after
applying power, the evaporator impeller (enclosure air) should start running. The compressor should then start
after a short delay. The condenser impeller may not start up immediately along with the compressor, but it should
start within a few more minutes as the system pressure increases.

© 2018 nVent 89145707
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DURING THIS INITIAL TEST AFTER THE CONDENSER IMPELLER HAS STARTED, CONFIRM THE
FOLLOWING:
1. The ambient temperature is displayed.
2. The Evaporator Fan Symbol is displayed when the evaporator impeller is running.
3. The Compressor Symbol is displayed when the compressor is running.
4. The Condenser Fan Symbol is displayed when the condenser impeller is running.
5. The Alarm Symbol is not displayed (assuming the ambient air temperature is in the normal
range between 40 (4 C) and 125 (52 C)).
6. The condenser outlet air temperature is warmer than surrounding ambient temperature within a
few minutes.
7. The enclosure outlet air temperature is cooler than surrounding ambient temperature.
INSTALLATION INSTRUCTIONS
1. Allow clearances per Table 1 - Airow Clearance (inches) and Table 2 - Service Clearance (inches):
TABLE 1 - AIRFLOW CLEARANCE (INCHES)
Front Left Side Right Side Top Bottom Evaporator Inlet* Evaporator Outlet*
12 0 0 3 0 3 3
* An air bae between the inlet and outlet may be necessary to prevent recirculation at minimum clearance levels.
TABLE 2 - SERVICE CLEARANCE (INCHES)
Front Left Side Right Side Top Bottom Enclosure Inlet** Enclosure Outlet**
24 417 6 0 N/A N/A
** Unit would have to be removed from enclosure to service this area.
2. Assure that cutouts in the enclosure match the cutout drawing, see Figure 1 on page 5.
3. Install mounting gaskets on the air conditioner, see Figure 3 on page 6. One gasket kit is
included with the unit.
4. Mount the air conditioner on the enclosure taking care not to damage the mounting gasket. The
mounting gasket seals between the air conditioner and the enclosure. Avoid dragging the air
conditioner on the enclosure with the mounting gasket attached as this could cause rips or tears
in the gasket and risk damaging the water tight seal.
5. Refer to the nameplate for electrical current requirements. Wire the unit to a properly grounded
power supply using copper conductors only. Shielded wires are recommended. Restrain the power
supply wiring to ensure there is no contact with internal fan. Minimum circuit ampacity should
be at least 125% of the amperage shown on the unit nameplate. No other equipment should be
connected to this circuit to prevent overloading. Electrical circuit should be fused with slow blow
or HACR circuit breaker.
6. Connect user-supplied door switch if desired.
7. Allow unit to remain upright for a minimum of ve (5) minutes before starting.
Air conditioner must be in an upright position during operation to
avoid damaging the air conditioner unit.
CAUTION

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28100013
89059115
Surface Mount
Partial Recess Mount
Cut-out Drawing
Figure 1

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CONTROLLER
INTERFACE
(AMBIENT
LOCATION)
15.05
382.2
.98
25
.65
16.6
10.18
258.7
17.01
432.1
ACCESS HOLE TO
.375 [9.5] OD DRAIN STUB
11.38
288.9
REMOVABLE
HANGING
TABS (2)
.57
14.5
(5)
15.87
403.1
(4)
7.55
191.8
15.26
387.6
1.26
31.9
14.00
355.6
14.20
360.6
4.64
117.7
.91
23.2
6.50
165.1
(2)
6.50
165.1
(2)
6.13
155.7
6.30
160
6.87
174.5
(2)
5.52
140.2
1.26
31.9
(2)
5.12
130
10.82
274.8
19.31
490.6
1/4-20 UNC MOUNTING HOLES (11)
POWER INPUT
HTR ACCESS
(OPTIONAL)
CONTROLLER
INTERFACE
(ENCLOSURE
LOCATION)
FUSES
CLEANABLE, REUSABLE
ALUMINUM INLET FILTER
REMOVAL OUT SIDES
NOTE:
APPROVED TO TYPE 3R/4/12.
1.
MOUNTING GASKET SUPPLIED (NOT SHOWN). 2.
89145842 Rev. B
Detail Drawing
Figure 2
Applying Gasket
Figure 3

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OPERATING THE AIR CONDITIONER
GENERAL
A parametric controller, in combination with a digital display, controls air conditioner operation. Temperature
scale (°F or °C), cooling set-point, cooling differential, cooling differential +/-, high/low temperature alarm set-
points, and language are among the parameters the user can view and set through the display. Alarms are shown
on the display, and are also output as a general alarm through a dry relay contact.
Cooling mode is initiated when the enclosure temperature rises above the Cooling ON Temperature and
the compressor is energized. The air conditioner is equipped with a feature that regulates head pressure by
controlling the condenser impeller. The condenser impeller runs when the pressure rises above a predetermined
value and stops when the pressure drops.
The controls are designed to prevent the air conditioner from running in the cooling mode if the enclosure
temperature is lower than 72 F. This decreases the likelihood of frost buildup on the evaporator coil.
The amount of moisture that the enclosure air can contain is typically limited since most enclosures are
substantially sealed. Water owing from the drain tube continuously indicates the enclosure is poorly sealed
and ambient air is entering the enclosure. Be aware, frequent opening of the enclosure door can admit a
signicant amount of humid air as well. In humid environments, the evaporator coil will use a signicant portion
of its cooling potential to dehumidify the air, which reduces the amount of heat it can remove, and increases the
amount of condensed water that must be managed.
DIGITAL DISPLAY
HOME SCREEN:
The enclosure temperature is the most prominent feature on the home screen of the digital display.
Symbols are displayed directly below the temperature to indicate the status of the alarm, the compressor,
the ambient fan, the enclosure fan and the heater (for models that include a heater). Reference Figure 4
and Table 3 - Home Screen Symbols on page 8.
Normally the home screen will display continuously. When applicable, the compressor restart delay
countdown, and descriptions of all active alarms, will display in sequence alternating with the home
screen.
Home Screen
Figure 4

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TABLE 3 - HOME SCREEN SYMBOLS
DESCRIPTION SYMBOL ICON ON
Alarm Alarm ACTIVE
Evaporator Fan Evaporator Fan ON
Compressor Compressor ON
Condenser Fan Condenser Fan ON
Heater
(only if present) Heater ON
INTERACTING WITH THE DIGITAL DISPLAY
NOTE: The display will revert to the home screen if no buttons are pressed for one minute. All
previously unsaved changes will be lost.
Button Symbol Description of Function
SELECT
When at the Home screen:
• The SELECT button will move the display to the main menu screen.
When at a screen with a list of selectable menu items:
• If the selected item is a menu, the SELECT button will move the display to the
selected menu screen.
• If the selected item is a parameter value, the SELECT button will save and use the
selected value for that parameter. The display will then move back to the previous
screen.
When at a screen with a numerical entry:
• The SELECT button will save and use the currently displayed value for the selected
parameter. The display will then move back to the previous screen.
BACK
When at the Home screen:
• The BACK button will have no effect.
When at a screen with a list of selectable menu items:
• The BACK button will move the display back to the previous screen. No parameters
will be altered or saved.
When at a screen with a numerical entry:
• The BACK button will move the display back to the previous screen. No value will be
altered or saved.
UP ARROW
When at the Home screen:
• The UP ARROW button will scroll up through the present values of the temperature
sensors each time the button pressed.
When at a screen with a list of selectable menu items:
• The UP ARROW button will scroll up to the item above the current menu item on the
screen. If at the top menu item, no action will be performed.
When at a screen with a numerical entry:
• The UP ARROW button will increase the value. If already at the maximum permitted
value, no action will be performed.
DOWN ARROW
When at the Home screen:
• The DOWN ARROW button will scroll down through the present values of the
temperature sensors each time the button pressed.
When at a screen with a list of selectable menu items:
• The DOWN ARROW button will scroll down to the item below the current menu item
on the screen. If already at the bottom menu item, no action will be performed.
When at a screen with a numerical entry:
• The DOWN ARROW button will decrease the value. If already at the minimum
permitted value, no action will be performed.

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User Interface
Cooling Set-Point
Cooling Differenal
Home Screen Main MenuHigh Temp Alarm
Enclosure Temp User Interface Low Temp Alarm
Alarm (if acve) System Interface Temperature Scale
Heater ON (if on) AboutDifferenal +/-
Cond fan ON (if on) Language
Evap fan ON (if on)Passcode
Compressor ON (if on)
Restart Delay Countdown
Cond Coil Temp or System Interface
Door Switch
Disable Switch
Alarm Relay Output
Comp Restart Delay
Comp Current System Sengs
System SengsCurrent Limit Seng
MALF Acvate
MALF Deacvate
AboutHPC Fan On
Control Hardware versionHPC Fan Off
Control Firmware version
Display Hardware version
Display Firmware version
10/24/17
Display Menu Structure
Figure 5
MAIN MENU CHOICES
• User Interface menu
>Factory default setting is passcode OFF. No passcode required to access.
>If passcode ON was previously set by the user, passcode 22 is required to access.
• System Interface menu
>Requires passcode 66 to access
• About
>When selected, it shows the control hardware and rmware versions, and the display hardware and rmware
versions.
USER INTERFACE MENU CHOICES
• Cooling Set-Point (view/set)
• Cooling Differential (view/set)
• High Temp Alarm (view/set)
• Low Temp Alarm (view/set)
• Temperature Scale (view/set Fahrenheit or Celsius)
• Differential +/- (view/set Positive or Negative)
• Language (view/set)
• Passcode (view/set passcode OFF or ON)
SYSTEM INTERFACE MENU CHOICES
• Door Switch (view/set Normally Open NO or Normally Closed NC)
• Disable Switch (view/set NO or NC)( Do not use - Not fully implemented)
• Alarm Relay Output (view/set NO or NC)
• Comp Restart Delay (view/set restart delay)
• Comp Current (view only)
• System Settings (view only)
SYSTEM SETTINGS MENU CHOICES
• Current Limit Setting (view only)
• MALF Activate (view only)
• MALF Deactivate (view only)
• HPC Fan On (view only)
• HPC Fan Off (view only)

© 2018 nVent 89145707
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TABLE 4 - CONTROL PARAMETERS AND SETTINGS
Control Parameter Units Default Range Additional conditions/comments
Cooling Set-Point Degrees 80 F
(26.6 C) 72 – 131 F (22.2 – 55.0 C)
When Differential +/- is changed,
the set point will automatically
be adjusted to maintain the same
cooling on and cooling off points.
When Differential +/- is set to
positive, the upper range of 131 F
(55.0 C) will be reduced by the value
set for the Cooling Differential.
When Differential +/- is set to
negative, the lower range limit of 72 F
(22.2 C) will be raised by the value set
for the Cooling Differential.
Cooling
Differential Degrees 7 F (3.8 C) 3 – 20 F (1.6 - 11.1 C)
The upper limit of 20 F (11.1 C) may
be reduced to prevent a violation of
the Cooling Set-Point range due to
the adjustment of the Cooling Set-
Point and/or Differential +/-.
Differential +/- -Positive Positive or
Negative
Changing the Differential +/- will
change the Cooling Set-Point and
may change the Cooling Differential,
see above.
High Temp Alarm Degrees 125 F
(51.6 C) 100 – 140 F (37.7 – 60.0 C)
Low Temp Alarm Degrees 40 F
(4.4 C) 0 – 60 F (-17.7 – 15.5 C)
Temperature Scale -°F °F or °C
Language -English Various Check display menu list for
preprogrammed languages
Passcode (User
Interface) -OFF ON or OFF
When ON (enabled), the user
interface passcode will be 22 and
cannot be changed
Passcode (System
Interface) -66 66
System Interface passcode cannot
be disabled and cannot be changed
from 66
Door Switch -Normally Closed Normally Open or
Normally Closed
Alarm output -Normally Open Normally Open or
Normally Closed
Compressor
restart delay Minutes:Seconds 5:00 3:00 – 5:00
Disable switch
input -Normally Open Normally Open or Normally Closed
Standard models are not wired for
this option and to maintain normal
operation this must be set to
Normally Open

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CONTROLLER PARAMETERS
COOLING SET-POINT
Cooling Set-Point denes the enclosure temperature that the air conditioner attempts to maintain. The range
limits for the Cooling Set-Point are not xed. The limits are constrained by the settings for Differential +/- and
Cooling Differential to prevent operation below 72 F (22 C) and to begin cooling before 131 F (55 C).
DIFFERENTIAL +/-
The Differential +/- parameter can be either Positive or Negative, and species how the Cooling Differential
is applied to the Cooling Set-Point to determine when cooling turns on and off. When Positive, the Cooling
Differential is added to the Cooling Set-Point. When Negative, it is subtracted from the Cooling Set-Point. When
switching from Positive to Negative Differential +/- settings, or vice versa, the Cooling Set-Point adjusts such that
cooling will start and stop at the same enclosure temperatures.
The example in the table below describes the effect on the temperature at which cooling turns on and cooling
turns off when the Cooling Set-Point and Cooling Differential are the same value. With Positive Differential +/-,
cooling starts at the Cooling Set-Point plus the Cooling Differential and ends at the Cooling Set-Point. With
Negative Differential +/-, cooling starts at the Cooling Set-Point and ends at the Cooling Set-Point minus the
Cooling Differential.
TABLE 5 - DIFFERENTIAL
Differential +/- Set-Point Differential Cooling turns on Cooling turns off
Positive 80 F (26.6 C) 7 F (3.8 C) 87 F (30.5 C) 80 F (26.6 C)
Negative 80 F (26.6 C) 7 F (3.8 C) 80 F (26.6 C) 73 F (22.7C)
COOLING DIFFERENTIAL
The cooling differential is the difference between when cooling turns on and off. The lower limit is 3 F (1.6 C).
The absolute upper limit is 20 F (11.1 C), but the actual upper limit may be reduced if required by the controller
software. The software will only offer a value to the user that results in cooling within the allowable range. See
Table 5 - Differential
The differential directly effects on the rate at which the compressor cycles on and off, and consequently the
temperature swing and compressor wear. See Table 6 - Cooling Differential.
TABLE 6 - COOLING DIFFERENTIAL
Differential Temperature Swing Compressor Cycle Rate and Compressor Wear Compressor Cycle Time
Increase differential ↑ ↓ ↑
Decrease differential ↓ ↑ ↓
TEMPERATURE SCALE
The temperature scale species whether temperatures are Fahrenheit or Celsius. When switching from one to the
other, all temperatures are converted automatically to the new units. As an example, if the cooling set-point is 95
F and the temperature scale is changed to Celsius, the set-point will be converted to 35 C.

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CONTROLLER FEATURES
AUTOMATIC PHASE CORRECTION
The controller incorporates automatic phase correction. The controller analyses the incoming, 3-phase sequence
each time power is applied and activates the appropriate relay to ensure correct phase sequencing regardless of
the actual wiring connections.
RANDOM START
A random start function varies the length of time the controller takes to complete its start-up sequence, from 30
to 90 seconds. This feature prevents motors of adjacent air conditioners from all starting at the same time, thus
minimizing the peak startup current when power is restored after a power outage, for example.
ENCLOSURE FAN CONTROL
The enclosure fan runs whenever power is applied to the unit. No option is available to alter enclosure fan control.
CONDENSER FAN CONTROL (HPC)
The condenser fan runs only when the compressor is running, and is further controlled to maintain optimal
system pressure during cold weather operation. This function relies on the condenser coil temperature sensor
to detect pressure. The fan is de-energized when the sensor temperature is below the HPC Fan Off setting
indicating low pressure that can occur during cooler ambient conditions. The fan is re-energized when the sensor
temperature is above the HPC Fan On setting indicating that the pressure has returned to a normal range.
PRESSURE MALFUNCTION ALARM (MALF)
Pressure malfunction alarm relies on the condenser coil temperature sensor and is activated when the system
pressure increases indicating a problem such as a clogged lter or a problem with the condenser fan. The alarm
is deactivated when the pressure returns to a normal range.
CONDENSER COIL TEMPERATURE SENSOR
The condenser coil temperature sensor reading can be viewed at any time by pressing the up or down arrow
button on the front panel of the controller display. The display will revert to displaying the evaporator inlet air
temperature reading after 60 seconds. The sensor can also be read through the Ethernet and USB connections.
COMPRESSOR RESTART TIME DELAY
The compressor and condenser fan will turn off when the enclosure inlet reaches the temperature at which
cooling turns off. To prevent compressor short cycling, a restart delay timer is set whenever the compressor turns
off. The timer counts down and prevents the compressor from restarting until the time has expired. The default
delay is 5 minutes.
DOOR SWITCH (OPTIONAL)
A dry contact for connection of a user-supplied door switch is provided via the two white 20 AWG wires located
on the enclosure side of the air conditioner (optional). The door switch input can be congured through the
Service Interface menu to normally open or normally closed. Default is normally closed with the wires jumpered
using a mechanical connector. If required, this input can accommodate inputs from a variety of other devices
such as a smoke detector. Multiple inputs can be used if wired in series.
ALARM RELAY OUTPUT (OPTIONAL)
A dry contact alarm output is provided with a 250 VAC load rating of 4 A resistive. Two yellow 20 AWG wires
located at the back of the air conditioner provide the connection to this output (optional). The Alarm Relay
Output can be congured through the Service Interface menu to normally open or normally closed. The default is
normally open so that the circuit is open when no alarm is present.
DISPLAY ALARM STATUS
There are twelve possible non-latching alarm conditions detectable by the controller. These alarms are indicated
on the controller display, and can also be accessed through the Ethernet and USB connections. See Table 7 -
Alarm Condition Display on page 13.
HIGH TEMP SHUTDOWN
The compressor will shut down and the message “High Temp Shutdown” will be displayed if the enclosure
air temperature goes above 149 F (65.0 C). The compressor will restart and the message will clear when the
temperature falls below 131 F (55.0 C).
EVAPORATOR COIL FREEZE PROTECTION (OPTIONAL)
If the enclosure outlet air temperature drops such that there is a possibility of ice building up on the coil, an
alarm is activated, and the compressor and condenser fan turn off. The alarm will clear, and the compressor and
condenser fan will restart when the air temperature rises back up to an acceptable level.

© 2018 nVent
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TABLE 7 - ALARM CONDITION DISPLAY
Alarm or
Information Text Details/Explanation Result Possible Cause and Recommended Action Alarm Relay
High Temp Alarm
Cabinet high
temperature (Alarm
clears at set-point
minus 2 F (1.1 C))
No effect on unit
function
Check for clogged air lter or
coil. Check fans and compressor,
for refrigerant leak or frozen
evaporator coil. ACU sized
incorrectly
Contacts
Activate
Low Temp Alarm
Cabinet low
temperature (Alarm
clears at set-point plus
2 F (1.1 C))
No effect on unit
function
Consider lowering the set-point or
adding an enclosure heater
Contacts
Activate
Door Alarm Door open Unit turns off for
duration of alarm
Close door, check wiring to door
switch circuit
Contacts
Activate
Phase Missing Any one of the three
input phases is missing
Unit turns off for
duration of alarm
Check supply wiring, fuses and
internal wires to compressor and
to fuses
Contacts
Activate
Compressor
Thermal Overload
Compressor over
temperature
Compressor turns off
for duration of alarm
Check air lter. Check for bad
condenser fan or bad compressor.
Contacts
Activate
Compressor
Overcurrent Alarm
Compressor current
above limit
Compressor turns off
for duration of alarm
Check air lter. Check for bad
condenser fan or bad compressor
Contacts
Activate
Controller Board
Malfunction
Controller senses
current ow when not
expected, or none when
expected
Unit turns off for
duration of alarm
Compressor harness shorted
or open, harness not properly
connected, bad compressor, or
bad controller
Contacts
Activate
Unit Malfunction:
High Pressure
Condenser coil
temperature exceeds
the MALF Activate set
point
No effect on unit
function
Check air lter and condenser fan
operation
Contacts
Activate
Enclosure Inlet
Air Temp Sensor
Malfunction
Temperature Sensor
Failure
Unit turns off for
duration of alarm
Check temp sensor.
Replace temp sensor.
Contacts
Activate
Condenser Coil
Temp Sensor
Malfunction
Temperature Sensor
Failure
Disables MALF and
HPC functions for
duration of alarm.
Condenser fan runs
continuously during
cooling.
Check temp sensor.
Replace temp sensor.
Contacts
Activate
High Temp
Shutdown
Cabinet temperature
above 149 °F (65.0 C) Shut down the compressor
Check for:
Clogged air lter or coil
Bad fans or compressor
Refrigerant leak
Frozen evaporator coil
Incorrectly sized ACU
Contacts
Activate
Display Error
Communication error
between control board
and display
No effect on unit
function
Bad display or bad control board.
Check display ribbon cable
connections.
No action
Restart Delay
Active
XX:XX Time
Remaining
Compressor restart
delay active
Compressor will
restart when time
remaining drops to
00:00
Frequent restart delay may
indicate the need to review cabinet
airow, ACU sizing or Cooling
Differential setting.
No action
Frost Detected
Compressor and
condenser fan
disabled
Freeze Protection
Function Enabled
Compressor and
condenser fan turn
OFF for the duration of
the alarm
Cooling set-point too low, or low
ambient temp No action
REMOTE ACCESS CONTROL
The optional Remote Access Control offers communication capabilities that extend those described in this
instruction manual. Please refer to the Remote Access Control manual for instructions and other information
related to this option.

© 2018 nVent 89145707
- 14 -
WHT
WHT
RED
BRN
BLK
RED
BRN
RED RED
BRN BRN
RED
BRN
BLK
BRN
RED
WHT
WHT
BLK
BRN
BLK
BRN
BLU BLU
BRN
BLK
GRN/YEL GRN/YEL
BLK
BRN
BLU
WHT WHT
WHT
WHT
BLK
BLK
BLK
BLK
YEL
YEL YEL
YEL
GRN/YEL
BLK
BRN
BLU
GRN/YEL
BLK
BRN
BLU
RED RED
89129335 REV: H
BLU
BLK BLK
BLK
GRN
RED
RED
BLK
GRN
ORG
ORG
WHT
WHT
GRN/YEL
GRN/YEL
OUTER ELECTRICAL SHIELD
BLK BLK
LEAD/LAG AND MASTER/SLAVE
Wiring Diagram
Figure 6

© 2018 nVent
89145707 - 15 -
MAINTENANCE
COMPRESSOR
The compressor requires no maintenance. It is hermetically sealed, properly lubricated at the factory and should
provide years of satisfactory operating service.
Under no circumstances should the access tting covers be loosened, removed or tampered with.
Breaking of seals on compressor access ttings during warranty period will void warranty on hermetic system.
Recharging ports are provided for the ease and convenience of reputable refrigeration repair service personnel for
recharging the air conditioner.
INLET AIR FILTER
This air conditioner was designed with a dust resistant condenser coil. This allows it to be run lterless in most
applications. The air conditioner is shipped with a lter in place for your convenience. For lterless operation,
simply remove the lter. Should you decide the lter is necessary in your application, regular maintenance to
clean this lter will assure normal operation of the air conditioner. The easily removable inlet air lter is located
behind the front cover. If necessary lter maintenance is delayed or ignored, the maximum ambient temperatures
under which the unit is designed to operate will be decreased.
If the compressor’s operating temperature increases above designed conditions due to a dirty or clogged lter
(or plugged condenser coil), the air conditioner’s compressor will stop operating due to actuation of the thermal
overload cut-out switch located on the compressor housing. When the compressor stops operating, the restart
delay is set. When the compressor temperature has dropped to within the switch’s cut-in setting, the compressor
will restart. However, the above condition will continue to occur until the lter or coil has been cleaned. It is
recommended that power to the air conditioner be interrupted intentionally when abnormally high compressor
operating temperature causes automatic shut-down of the unit. The above described shut-down is symptomatic
of a clogged or dirty lter, thus causing a reduction in cooling air ow across the surface of the compressor and
condenser coil.
HOW TO REMOVE, CLEAN OR INSTALL A NEW INLET AIR FILTER
RP aluminum washable air lters are designed to provide excellent ltering eciency with a high dust holding
capacity and a minimum amount of resistance to air ow. Because they are constructed entirely of aluminum,
they are lightweight and easy to service. To achieve maximum performance from your air handling equipment, air
lters should be cleaned on a regular basis.
The inlet air lter is located behind the front access cover. To remove lter, push or pull to slide lter out from
either side of the unit. The lter may now be cleaned or a new lter installed.
Cleaning Instructions:
1. Flush the lter with warm water from the exhaust side to the intake side. DO NOT USE CAUSTICS.
2. After ushing, allow lter to drain. Placing it with a corner down will assure complete drainage.
CONDENSER AND EVAPORATOR AIR MOVERS
Impeller motors require no maintenance. All bearings, shafts, etc. are lubricated during manufacturing for the life
of the motor.
If one of the condenser impeller motors (ambient impellers) should fail, it is not necessary to remove the air
conditioner from the cabinet or enclosure to replace the blower. The condenser impeller is mounted on its own
bulkhead and is easily accessible by removing the front cover. The enclosure impeller is mounted on a removable
plate and can be accessed through the enclosure access panel.
Operation of the air conditioner in areas containing airborne
caustics or chemicals can rapidly deteriorate lters, condenser
coils, blowers and motors, etc. Contact nVent Equipment
Protection for special recommendations.
CAUTION

© 2018 nVent 89145707
- 16 -
REFRIGERANT LOSS
Each air conditioner is thoroughly tested prior to leaving the factory to insure against refrigeration leaks. Shipping
damage or microscopic leaks not found with sensitive electronic refrigerant leak detection equipment during
manufacture may require repair or recharging of the system. This work should only be performed by qualied
professionals, generally available through a local, reputable air conditioning repair or service company.
Should the refrigerant charge be lost, access ports on the suction and discharge sides of the compressor are
provided for recharging and/or checking suction and discharge pressures.
Refer to the data on the nameplate which species the type of refrigerant and the charge size in ounces.
Before recharging, make sure there are no leaks and the system has been properly evacuated into a deep
vacuum.
TABLE 8 - REFRIGERANT PROPERTIES CHART (R 134A)
°F °C Pressure
(PSIG) °F °C Pressure (PSIG)
-40 -40 -14.7 60 15.6 58
-35 -37.2 -12.3 65 18.3 64
-30 -34.4 -9.7 70 21.1 71.5
-25 -31.7 -6.8 75 23.9 78
-20 -28.9 -1 80 26.7 86.7
-15 -26.1 085 29.4 95
-10 -23.3 290 32.2 105
-5 -20.6 495 35 113.3
0-17.8 7.5 100 37.8 125
5-15 9105 40.6 135
10 -12.2 12 110 43.3 146.7
15 -9.4 15 115 46.1 157.5
20 -6.7 18.5 120 48.9 170
25 -3.9 22 125 51.7 185
30 -1.1 26
35 1.7 30
40 4.4 35
45 7.2 40
50 10 45.5
55 12.8 51.5
TABLE 9 - FUNCTIONAL DATA
Unit Evaporator. Air
In(°F) Amps(A) Evap Pressure (PSIG)
Cond
Pressure
(PSIG)
Condenser
Delta(°F) Evaporator Delta(°F)
G280(4/6)46GXXX 65-80 1.1 - 1.4 23 - 38 99 - 166 16 - 34 16 - 35
80-100 1.1 - 1.6 31 - 57 136 - 245 18 - 40 19 - 41

© 2018 nVent
89145707 - 17 -
TABLE 10 - UNIT CHARACTERISTICS
Part Number
G280446GXXX G280646GXXX
Dimensional Data
Height (in./mm) 28.55/725.2
Width (in./mm) 16.97/431.1
Depth (in./mm) 10.10/256.6
Unit Weight (lb./kg) 84/38
Unit Protection Rating Type 12/4/4X/3R
Cooling Data
Refrigerant R134A
Refrigerant Charge 16 oz.
Cooling Capacity at 95 F Enclosure 95 F Ambient (BTU/Hr./W) 4324/4655 5054/5685
Cooling Capacity at Max Conditions (BTU/Hr./W) 4600/4900 5400/6000
Maximum Ambient Temp (°F/°C) 131/55
Minimum Ambient Temp (°F/°C) -40/-40
Enclosure Airow 189/221 CFM
External Airow 291/300 CFM
Heating Data
Capacity N/A
Electrical Data
Rated Voltage (50/60 Hz) 400/460V 3-Phase
Rated Frequency 50/60 Hz
Voltage Range +/- 10% of rated
Cooling Amps at Max Conditions 1.7/1.9
Compressor RLA / LRA 1.7/7.7
Evaporator Fan RLA 0.15
Condenser Fan RLA 0.21

© 2018 nVent 89145707
- 18 -
SERVICE DATA
TABLE 11 - COMPONENTS LIST
Part Description
Part Number
G280446GXXX
G280646GXXX
Coil, Condenser 89051206SP
Coil, Evaporator 28601000SP
Communication Board 89145457SP
Communication Cable RS485 89156343SP
Compressor 10102695SP
Thermal Overload, Compressor 10100777SP
Controller, 460V 3-Phase 89127835SP
Filter Air, Reusable 89096883SP
Filter/Dryer 52602800SP
Impeller Condenser 89128200SP
Impeller Evaporator 89128198SP
Thermal Expansion Valve 89063955SP
Fuse 10 Amp 89128646SP
Temperature Sensor, Inlet Air 093008116SP
Temperature Sensor, Condenser Coil and Evaporator Outlet 89131494SP
For additional technical support, contact nVent Equipment Protection at 800-896-2665.

© 2018 nVent
89145707 - 19 -
NOTES

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