White Lightning M Series User manual

M-Series Operator’s Manual
Model M2850, 28-Volt 50-Amp Mini-GPU
IMPORTANT DISCLAIMERS & LIABILITY LIMITATIONS
As a condition for use, Audio Authority Corp. authorizes this device for use ONLY by aviation
professionals, such as licensed pilots and maintenance technicians, knowledgeable about the
aircraft’s electrical system and batteries. The concepts, recommendations, and instructions in this
manual are necessarily general and make assumptions that may not apply to your aircraft. Therefore,
incorrect use of this device has the potential to damage the GPU and/or aircraft components.
The device is designed exclusively for aircraft with a 28VDC electrical system, a 24V battery, and a
factory-installed external power receptacle for a 3-pin oval AN2551 (NATO) plug.
It is the operator’s sole responsibility to read completely and fully understand this manual, plus all
available documentation on their aircraft’s electrical system design, to properly determine the
appropriate use of this, or any, external power source. If you cannot do this, do not use this
product. Instead, consult a qualified technician familiar with your specific aircraft type and
configuration before connecting the GPU to your aircraft, or return it to the seller before using.

M-Series M2850 GPU Manual P/N 752-794, Rev 20220801 2
General Description and Application
The M2850 Mini-GPU is a specialized switching-mode power supply designed to provide pilots and
aviation maintenance professionals with a portable, affordable source of stable, high-current, noise-free
DC power that replicates the in-flight electrical environment. Its rated output is 28-volts up to 50-amps
(approximately 1500 watts). The GPU’s intended purpose is to energize an aircraft’s main electrical bus
without using the ship’s battery or engine. It will safely provide continuous power for the most delicate
electronics and airframe systems up to its full rated output.
Typical Uses
● power avionics for flight planning, familiarization, and training
● update flight deck database and software
● troubleshooting and maintenance
FRONT PANEL VIEW REAR PANEL VIEW
Special Features
● Color-coded, keyed SB-50 type output connection to prevent accidental voltage mismatch –
RED designates 24/28 volt compatibility.
● Dual digital output meters for voltage and amperage (load)
● Front panel status indicator LED
● Programmable auto-shutdown timer and dual USB power ports for mobile device charging
● QuietFiltered™ output for interference-free COM radio operation
● Auto protection/recovery from short circuit, reverse polarity, over voltage/load/temperature
Operating Conditions and Limitations
The M2850 is internally fan-cooled and relies on unobstructed ventilation access for proper operation.
The GPU should operate on a clean, hard surface so that debris cannot be ingested. Its design assumes
a dry operating environment. If used outdoors, it is the operator’s responsibility to ensure that the unit is
not exposed to moisture.
The M2850 is designed to provide airframe power only. It is not a battery charger. It does not monitor
the state-of-charge of the aircraft battery. It is not suitable for engine starting.

M-Series M2850 GPU Manual P/N 752-794, Rev 20220801 3
Safety Precautions
● Do not use this or any electrical device near uncontained fuel or fuel vapors.
● Use in a well-ventilated area.
● Do not use in a wet environment.
● Do not use in the presence of open fuel containers or if fuel vapors are detected.
● Disconnect GPU from aircraft when not in use.
● Do not leave unattended while in use.
Connecting GPU to Aircraft
● Connect the GPU AC input cord to a grounded power receptacle, 90-240VAC, 50-60Hz.
● Connect the output cable to the GPU front panel receptacle.
● Turn GPU power switch ON; observe as proper voltage stabilizes on the output display.
● Connect GPU output cable to aircraft’s external power receptacle; observe that the airframe is
energized and shows a stable load of less than the GPU’s rated output. If voltage or current load
are not as expected, or GPU status indicator is flashing or red, disconnect the GPU from the
airframe and investigate the problem.
SAFETY TIP: Using the GPU during preflight allows time for a thorough inspection of all systems
and lights, without depleting the aircraft battery. In fact, if the battery is switched in-circuit with the
external power, it will provide a “top-off” charge for the aircraft battery. (Not to exceed 15 minutes.)
Status Indicator
The GPU incorporates a status indicator between the volt/amp meter and the output connector.
Indications are interpreted as follows:
OFF
Power Switch OFF, or no AC input power
GREEN
ON or powered, normal operation
FLASHING GREEN
Auto-shutdown engaged
FLASHING RED
Fault condition – see troubleshooting table for more details
Automatic Shutdown Timer
The M2850 features a programmable timer to automatically shut down the GPU after a period of time in
use, as selected by the user. This is to prevent the GPU from inadvertently being left on for an extended
period and potentially overcharging the aircraft’s battery, if in-circuit with the GPU.
A 10-position rotary switch on the back panel determines the duration of continuous operation. Each
number represents ½hour. This switch is factory set at 5 (2.5 hours); adjust with a small screwdriver. To
disable the auto-shutdown feature, set the switch to the 0 position.
To reset the timer and restart the GPU after auto-shutdown, cycle the power switch OFF then back ON.
USB Mobile Device Charging
Two convenience USB charging ports are provided on the rear panel of the GPU. These provide a 5VDC
output, up to 2A total combined, suitable for charging many portable devices like phones and speakers.

M-Series M2850 GPU Manual P/N 752-794, Rev 20220801 4
Troubleshooting
PROBLEM / CONDITION
CAUSE
SOLUTION
GPU does not turn ON
Volt/Amp meter OFF*
Status indicator OFF
No AC input to GPU.
Verify power cord connections.
Reset built-in circuit breaker by cycling
the ON/OFF switch.
If breaker blows repeatedly, GPU
needs to be repaired. See Limited
Warranty statement for technical service
contact information.
GPU displays voltage but no output
to aircraft (zero amps)
Status indicator GREEN
Faulty connection between
GPU and aircraft electrical
system.
Check connections from GPU to the
aircraft’s external power receptacle.
Volt/amp meter OFF*
Status indicator FLASHING GREEN
Auto-shutdown timer
expired.
Cycle power switch OFF, then back ON,
to restart shutdown timer.
Adjust timer settings if desired, or zero to
disable shutdown timer.
Status indicator FLASHING RED
Voltage drops to < 26 volts
Current overload.
Reduce load to less than 50 amps.
Status indicator FLASHING RED
Volt/Amp meter OFF
Internal protection engaged.
Over temperature, or
severe overload.
Reduce load to less than 50 amps.
Turn off aircraft equipment to reduce
current draw.
Cycle Power Switch OFF then ON again
to reset.
Status indicator FLASHING RED
GPU displays voltage but no output
to aircraft (zero amps)
Internal protection engaged.
If cable connections are good, then turn
power switch OFF.
Disconnect DC output cord from aircraft
external power receptacle. Wait for GPU
meter to go OFF.
Power switch ON. Observe meters ON.
Reconnect to aircraft.
* If there is battery voltage back feeding to the GPU from the aircraft, the voltmeter will display that condition, which may trigger
the GPU into protection mode and not turn back on if power is interrupted. Follow instructions above for disconnecting from the
aircraft and resetting the GPU to restore proper operation.
SPECIFICATIONS
M2850
Input Voltage
Universal 90-264 volts AC, 47-63 Hz
Input Current
17A @ 115 volts AC
Input Protection
20A circuit breaker, cycle ON/OFF to reset
Output
28.50 +/- 0.25 VDC, 50 amps max cont.
Output Cable
4 AWG, SB-50 to 3-pin oval AN2551 (NATO)
Chassis Dimensions
6.45” H x 5.32” W x 14.63” L
Carry Weight w/cables
17 lbs
Carton Dimensions
10” H x 10” W x 18” L
Shipping Weight
18.3 lbs

M-Series M2850 GPU Manual P/N 752-794, Rev 20220801 5
One Year Limited Warranty
All Mini-GPUs are warranted to the original purchaser to be free of defects in materials and workmanship
for a period of one year from date of shipment. If you suspect a failure, please contact our service
department for instructions or see our Service Policies online at
www.audioauthority.com/page/Service_policy.
Service Department
Audio Authority Corporation
2048 Mercer Road, Lexington, KY 40511
Phone: [phone] (or 859-233-4599)
Email: [e-mail]
Units received that are in-warranty will be repaired without charge. Units returned for service require a
return authorization number and must be shipped freight prepaid. Units repaired under warranty will be
returned freight prepaid via UPS ground or equivalent. A repair estimate will be provided for out-of-
warranty repairs. This warranty is void for products that, in our opinion, have been subject to overload,
moisture, accident, damage, alteration, misuse, abuse, or acts of nature.
THE SOLE AND EXCLUSIVE REMEDY UNDER THIS WARRANTY IS LIMITED TO REPAIR OR
REPLACEMENT AS SPECIFIED ABOVE. THERE ARE NO OTHER WARRANTIES EXPRESSED OR
IMPLIED. SPECIFICALLY, BUT WITHOUT LIMITATION, THERE ARE NO IMPLIED WARRANTIES OF
MERCHANTABILITY OR FITNESS FOR A PARTICULAR PURPOSE. IN NO EVENT WILL AUDIO
AUTHORITY BE RESPONSIBLE FOR ANY INCIDENTAL OR CONSEQUENTIAL DAMAGES ARISING
FROM ANY DEFECT, OR FAILURE TO OPERATE PROPERLY, OR ARISING OUT OF ANY BREACH
OF THE WARRANTY MADE HEREIN.
No person is authorized to give any other warranty or to assume any additional obligation or liability on
behalf of Audio Authority Corporation, without its express written approval.
Audio Authority Corp.
2048 Mercer Road
Lexington, KY 40511
800-322-8346 or 859-233-4599
[email protected]
AudioAuthority.com/aviation