Tesla TI4400 GPU-24 User manual

Tesla™TI4400 GPU-24
User Manual
Built Smart...Proven Tough
Power Anytime, Anywhere
Tesla Industries, Inc.
101 Centerpoint Blvd.
New Castle, DE 19720
[phone] Phone
[phone] Fax
www.teslaind.com
www.tesla1.com

NOTE: All users must read this entire manual prior
to operating the TI4400 GPU-24.
The TI4400 GPU-24 is a limited maintenance-free and sealed unit. No repairs are authorized. Warranty will
be voided if unit is tampered with in any way, or if unauthorized repairs are made. For technical support
please contact:
TESLA™ INDUSTRIES INCORPORATED
101 CENTERPOINT BLVD.
CENTERPOINT INDUSTRIAL PARK, NEW CASTLE, DELAWARE 19720
PHONE: [phone] FAX: [phone]
WEBSITE: www.teslaind.com ♦ www.tesla1.com EMAIL: t[email protected]
Shock Hazard Potential
CAUTION
Improper use or failure to follow instructions in this user manual can result in unit damage and/or injury or
death by electrical shock.
Any attempts to open or examine the inside of the unit via a tool or device (borescope, probe, etc.) can result
in unit failure and/or injury by electrical shock. This GPU is maintenance free and should not be opened or
disassembled for any reason.
Always protect the unit from short circuit.
Shipping Hazards: The unit contains sealed, dry cell rechargeable batteries that do not pose a shipping
hazard.
05-04-21
All Ground Power Units, Micro Power Units (Aviation Batteries) and including, but not limited to, Battery Chargers/
Conditioners, manufactured by Tesla™ Industries, Inc., are able to safely and effectively charge any AGM, Lead
Acid battery.
The Tesla™ GPU’s and chargers are voltage and current regulated to 0.01% (dual loop). The charging voltage is
calibrated, by Tesla™, to 28.6 volts and is pure dc (no power line ripple).
Maximum Charge Voltage by Battery Type
Type: Charging Voltage / Cell Charging Voltage / 12v Charging Voltage / 24v
SLI/Flooded 2.366v to 2.416v 14.2v to 14.5v 28.4v to 29v
Lead Acid/Flooded 2.366v to 2.416v 14.2v to 14.5v 28.4v to 29v
Sealed Lead Acid 2.366v to 2.416v 14.2v to 14.5v 28.4v to 29v
VRLA 2.366v to 2.416v 14.2v to 14.5v 28.4v to 29v
AGM 2.433v to 2.466v 14.6v to 14.8v 29.2v to 29.6v
GEL 2.350v to 2.400v 14.1v to 14.4v 28.2v to 28.8v
Copyright © 2021 by Tesla™ Industries, Incorporated. All rights reserved.

Form #: SDS 853027
Revised: AG
Supersedes: AF
ECO #: 1002195
I. PRODUCT IDENTIFICATION
Chemical Trade Name (as used on label):
Tesla™ Industries, Inc.
Chemical Family/Classification:
Sealed Lead Battery
Synonyms:
Sealed Lead Acid Battery, VRLA Battery Telephone:
For information, contact Tesla™ Industries, Inc.
Manufacturer's Name/Address:
Customer Service Department at 302-324-8910
Tesla™ Industries, Inc
101 Centerpoint Blvd. 24-Hour Emergency Response Contact:
New Castle, DE 19720-4180 CHEMTREC DOMESTIC: 800-424-9300 CHEMTREC INT'L: 703-527-3877
II GHS HAZARDS IDENTFICATION
Acute Toxicity
(Oral/Dermal/Inhalation) Category 4
Skin Corrosion/Irritation Category 1A
Eye Damage Category 1
Reproductive Category 1A
Carcinogenicity (lead compounds) Category 1B
Carcinogenicity (acid mist) Category 1A
Specific Target Organ Toxicity
(repeated exposure) Category 2
GHS LABEL:
Hazard Statements Precautionary Statements
DANGER! Wash thoroughly after handling.
Causes severe skin burns and serious eye damage. Do not eat, drink or smoke when using this product.
May damage fertility or the unborn child if ingested or Wear protective gloves/protective clothing, eye protection/face protection.
inhaled. Avoid breathing dust/fume/gas/mist/vapors/spray.
May cause cancer if ingested or inhaled. Use only outdoors or in a well-ventilated area.
Causes damage to central nervous system, blood and Contact with internal components may cause irritation or severe burns. Avoid contact with internal acid.
kidneys through prolonged or repeated exposure. Irritating to eyes, respiratory system, and skin.
May form explosive air/gas mixture during charging. Obtain special instructions before use.
Explosive, fire, blast, or projection hazard. Do not handle until all safety precautions have been read and understood
May cause harm to breast-fed children Avoid contact during pregnancy/while nursing
Harmful if swallowed, inhaled, or contact with skin Keep away from heat./sparks/open flames/hot surfaces. No smoking
Causes skin irritation, serious eye damage.
III. COMPOSITION/INFORMATION ON INGREDIENTS
CAS Number
Approximate % by
Weight
Inorganic Lead Compound:
Lead 7439-92-1 45 - 60
Lead Dioxide 1309-60-0 15 - 25
Tin 7440-31-5 0.1 - 0.2
Sulfuric Acid Electrolyte (Sulfuric Acid/Water) 7664-93-9 15 - 20
Case Material: 5 - 10
Polypropylene 9003-07-0
Polystyrene 9003-53-6
Styrene Acrylonitrile 9003-54-7
Acrylonitrile Butadiene Styrene 9003-56-9
Styrene Butadiene 9003-55-8
Polyvinylchloride 9002-86-2
Polycarbonate, Hard Rubber, Polyethylene 9002-88-4
Polyphenylene Oxide 25134-01-4
Polycarbonate/Polyester Alloy --
Other:
Absorbent Glass Mat -- 1 - 2
HEALTH
Components
SAFETY DATA SHEET
PHYSICAL
PHYSICAL
Explosive Chemical, Division 1.3
ENVIRONMENTAL
Aquatic Chronic 1
HEALTH
Aquatic Acute 1
ENVIRONMENTAL
Page 1

Form #: SDS 853027
Revised: AG
Supersedes: AF
ECO #: 1002195
SAFETY DATA SHEET
Inorganic lead and sulfuric acid electrolyte are the primary components of every battery manufactured by Tesla™ Products.
There are no mercury or cadmium containing products present in batteries manufactured by Tesla™ Products.
IV. FIRST AID MEASURES
Inhalation:
Sulfuric Acid: Remove to fresh air immediately. If breathing is difficult, give oxygen. Consult a physician
Lead: Remove from exposure, gargle, wash nose and lips; consult physician.
Ingestion:
Sulfuric Acid: Give large quantities of water; do not induce vomiting or aspiration into the lungs may occur and can cause permanent injury or death;
consult a physician
Lead: Consult physician immediately.
Skin:
Sulfuric Acid: Flush with large amounts of water for at least 15 minutes; remove contaminated clothing completely, including shoes.
If symptoms persist, seek medical attention. Wash contaminated clothing before reuse. Discard contaminated shoes
Lead: Wash immediately with soap and water.
Eyes:
Sulfuric Acid and Lead: Flush immediately with large amounts of water for at least 15 minutes while lifting lids
Seek immediate medical attention if eyes have been exposed directly to acid.
V. FIRE FIGHTING MEASURES
Flash Point: N/A Flammable Limits: LEL = 4.1% (Hydrogen Gas) UEL = 74.2% (Hydrogen Gas)
Extinguishing Media: Carbon dioxide; foam; dry chemical. Avoid breathing vapors. Use appropriate media for surrounding fire.
Special Fire Fighting Procedures:
If batteries are on charge, shut off power. Use positive pressure, self-contained breathing apparatus. Water applied to electrolyte generates
heat and causes it to spatter. Wear acid-resistant clothing, gloves, face and eye protection.
Note that strings of series connected batteries may still pose risk of electric shock even when charging equipment is shut down.
Unusual Fire and Explosion Hazards:
Highly flammable hydrogen gas is generated during charging and operation of batteries. To avoid risk of fire or explosion, keep sparks or other
sources of ignition away from batteries. Do not allow metallic materials to simultaneously contact negative and positive terminals of cells and
batteries. Follow manufacturer's instructions for installation and service.
VI. ACCIDENTAL RELEASE MEASURES
Spill or Leak Procedures:
Stop flow of material, contain/absorb small spills with dry sand, earth, and vermiculite. Do not use combustible materials. If possible, carefully
neutralize spilled electrolyte with soda ash, sodium bicarbonate, lime, etc. Wear acid-resistant clothing, boots, gloves, and face shield. Do not
allow discharge of unneutralized acid to sewer. Acid must be managed in accordance with local, state, and federal requirements.
Consult state environmental agency and/or federal EPA.
VII. HANDLING AND STORAGE
Handling:
Unless involved in recycling operations, do not breach the casing or empty the contents of the battery.
There may be increasing risk of electric shock from strings of connected batteries
Keep containers tightly closed when not in use. If battery case is broken, avoid contact with internal components.
Keep vent caps on and cover terminals to prevent short circuits. Place cardboard between layers of stacked automotive batteries to avoid damage and short circuits.
Keep away from combustible materials, organic chemicals, reducing substances, metals, strong oxidizers and water. Use banding or stretch wrap to secure items for
shipping.
Storage:
Store batteries in cool, dry, well-ventilated areas with impervious surfaces and adequate containment in the event of spills. Batteries should
also be stored under roof for protection against adverse weather conditions. Separate from incompatible materials. Store and handle only
in areas with adequate water supply and spill control. Avoid damage to containers. Keep away from fire, sparks and heat. Keep away from metallic objects which
could bridge the terminals on a battery and create a dangerous short-circuit
Charging:
There is a possible risk of electric shock from charging equipment and from strings of series connected batteries, whether or not being charged. Shut-off power to
chargers whenever not in use and before detachment of any circuit connections. Batteries being charged will generate and release flammable hydrogen gas.
Charging space should be ventilated. Keep battery vent caps in position. Prohibit smoking and avoid creation of flames and sparks nearby.
Wear face and eye protection when near batteries being charged.
VIII. EXPOSURE CONTROLS/PERSONAL PROTECTION
Exposure Limits (mg/m3) Note: N.E.= Not Established
OSHA PEL ACGIH US NIOSH Quebec PEV Ontario OEL EU OEL
0.05 0.05 0.05 0.05 0.05 0.15 (b)
2 2 2 2 2 N.E
10.2 1 1 0.2 0.05 (c)
N.E N.E N.E N.E N.E N.E
N.E N.E N.E N.E N.E N.E
N.E N.E N.E N.E N.E N.E
N.E N.E N.E N.E N.E N.E
N.E N.E N.E N.E N.E N.E
N.E N.E N.E N.E 1N.E
Polypropylene
Polyvinylchloride
INGREDIENTS
(Chemical/Common Names)
Lead and Lead Compounds
(inorganic)
Polystyrene
Styrene Butadiene
Tin
Sulfuric Acid Electrolyte
Styrene Acrylonitrile
Acrylonitrile Butadiene
Styrene
Page 2
For expanded detailed info, download the PDF online at...
http://www.teslaind.com/PDF/chart/Tesla-Safety-Data-Sheet.pdf.

TI4400 GPU-24
Table of Contents
Section 1 – Safety Review 1
1.1 – Safety Notices 1
1.2 – Symbols 1
1.3 – Hazards 2
1.4 – Important Safety Precautions 2
1.5 – Extreme Environments 2
Section 2 – Product Overview 3
2.1 – Introduction 3
2.2 – Indication of Terms: Shall, Should, and May 3
2.3 – Front Panel Overview 4
2.4 – General Specications 5
2.5 – Physical Dimensions 6
2.6 – Airow Ports 5
2.7 – Operating Position 7
2.8 – “Push to Test” Button and LED Status Indicator 8
2.9 – 60 Hz 3-Phase AC Input Circuit Breaker 9
2.10 – DVAM Interface Receptacle 9
2.11 – DC Output “ON” and “OFF” Buttons 10
Section 3 – Operating Procedures 11
3.1 – Operating Procedures 11
3.2 – General 11
3.3 – Operating Limits and Restrictions 11
3.4 – Performance 11
3.5 – Engine Starting Power 11
3.6 – Temperature Specications 12
3.7 – Environmental 13
3.8 – Operation 14
3.9 – Normal Functional Test Procedures 14-15
3.10 – Pre-Operation 16
3.10 – Transporting Unit 16
3.12 – Disabling DC Output Receptacle 16
3.13 – Regulated 28.5 Vdc Ground Power 17-18
3.14 – Regulated AC Power 19
3.15 – Charging Unit 19
3.16 – Operating with a Digital Volt/Amp Meter 20

TI4400 GPU-24
Section 4 – Post Operations 21
4.1 – General 21
4.2 – After Use 21
4.3 – Power Cell Recharge 21-22
Section 5 – Unit Care and Maintenance 23
5.1 – Unit Care 23
5.2 – Unit Servicing 24
5.3 – Packaging and Shipping 24
5.4 – Storage 24
Section 6 – Troubleshooting and FAQ 25
6.1 – Frequently Asked Questions 24-26
6.2 – Basic Usage/Operation Questions 27
6.3 – Basic Troubleshooting 28-29
Section 7 – Performance Data 30
7.1 – Purpose 30
7.2 – General 30
7.3 – Data Basis 30
7.4 – Specic Conditions 30
7.5 – General Conditions 30
7.6 – Temperature Conversion Chart 31
7.7 – Output Voltage 32
7.8 – Maximum Output Current 32
Section 8 – Optional Accessories 33
8.1 – Shipping Case 33
8.2 – GPU Protective Covers 33
8.3 – Digital Volt/Amp Meter (DVAM) 33
8.4 – Cobra™ DC Replacement Contacts and Tools 34
8.5 – GPU Tires 34
Repair Request Form 35

TI4400 GPU-24
Abbreviations and Symbols
Abbreviations that may be used within the text, headings and titles of this manual.
LIST OF ABBREVIATIONS
Abbreviation Defi nition
ac Alternating Current
AFT Air ow Technology
AWG American Wire Gauge
amp or A Ampere
cont Continuous
°C Degree Celsius
°F Degree Fahrenheit
dc Direct Current
EFF Ef ciency
ft Feet
FWD Forward
GPU Ground Power Unit
Hr Hour
Hz Hertz
kg Kilograms
kHz Kilohertz
kW Kilowatts
LED Light Emitting Diode
max Maximum
MΩ megaohm
min Minimum
MPU Micro Power Unit
NEMA National Electrical Manufacturers Association
Ω ohm
PF power factor
PFC power factor correction
rms root-mean-square
THD Total Harmonic Distortion
TMDE Test, Measurement, & Diagnostic Equipment
UAV Unmanned aerial vehicle
Vac Volts, Alternating Current
Vdc Volts, Direct Current
W watts

TI4400 GPU-24 1
Figure 1.2.1 – Different types of hazard and caution symbols
1.1 - Safety Notices
Safety notices appear throughout this manual to alert the user to important information regarding proper
installation, operation, maintenance and storage of the unit. These notices, as illustrated below, contain a
key word that indicates the level of hazard and a triangular icon that indicates the speci c type of hazard.
WARNING Indicates a condition, operating procedure or practice, which if not
adhered to could result in serious injury or death.
CAUTION Indicates a condition or operating procedure, which if not strictly
adhered to could result in damage or destruction of equipment.
NOTE Indicates a condition, operating procedure or practice, which is
essential to highlight.
1.2 - Symbols
The following symbols will appear within the warning triangles to alert the user to the speci c type of danger
or hazard.
General Warning Electrical Hazard Explosion Hazard Fire Hazard
Battery Warning Guard from Moisture
!
Section 1 – Safety Review
!
!
!

TI4400 GPU-24
2
1Safety Review
1.3 – Hazards
WARNING Shock Hazard Potential
Severe injury or death from electrical shock may occur, if either user
or the unit is wet, while the unit is connected to a power source. If the
unit has come into contact with water, disconnect ac power from the ac
source. If AC Input Circuit Breaker has tripped due to water in ltration,
DO NOT try to reset it with the ac line voltage attached.
Adapter with Grounding Mechanism
(hangar wall,  ight line ac power) prior to connecting the unit for
1.4 – Important Safety Precautions
WARNING Fire/Explosion Hazard Potential
Severe injury or death from  re or explosion can occur if electrical sparks are produced near fuel vapors. DO
NOT CONNECT ac power supply WHILE FUELING. AC power functions of unit shall not be operated during any
fuel handling operation. Power output is restricted to dc power only.
1.5 – Extreme Environments
CAUTION Unit Damage Potential
The unit’s charger temperature switch automatically disables the unit when the internal temperature exceeds
150°F (65°C). This protects the unit from overheating and damage. If the unit shuts down, move the unit
into a cooler environment such as shade or air conditioning when possible. Perform a full function test, after
the unit has been allowed to cool, prior to use.
WARNING Shock Hazard Potential
Severe injury or death from electrical shock can occur when damp electrical plugs are connected to the
unit. Before making any connections, turn off unit. Failure to use proper grounding can cause potential
shock hazard! In different countries, the power cord may require the use of a plug adapter to achieve plug
style compatibility for operation. Use only adapters with proper grounding mechanism.
source. If AC Input Circuit Breaker has tripped due to water in ltration,
Adapter with Grounding Mechanism
(hangar wall,  ight line ac power) prior to connecting the unit for

TI4400 GPU-24 3
Figure 2.1.1 – TI4400 GPU-24
2.2 – Indication of Terms: Shall, Should, and May
Within this technical manual the word “shall” is used to indicate a mandatory requirement for proper operation
and warranty purposes. The word “should” is used to indicate a non-mandatory but preferred method of
accomplishment. The word “may” is used to indicate an acceptable method of accomplishment.
Section 2 – Product Overview
2.1 – Introduction
Thank you and congratulations on the purchase of your new TI4400 GPU-24 Ground Power Unit.
The TI4400 GPU-24 provides dc electrical ground power for aircraft ight line, maintenance, and ground
support operations. The unit is designed to provide 24 volt dc electrical power output for vehicle and aircraft
engine starting and 24 or 28.5 volts dc electrical support for ground maintenance, avionics/electrical
troubleshooting and testing. The observance of procedures, limitations and performance criteria ensures
peak operating efciency and maximizes operational capabilities and life of the TI4400 GPU-24.
This manual contains the complete operating instructions and procedures for the TI4400 GPU-24 needed to
safely and efciently operate this GPU.

TI4400 GPU-24
4
2Product Overview
2.3 – Front Panel Overview
“Push to Test” Button1. – Displays current
battery charge state when pressed.
DC Output Receptacle2. – Provides output
of 28.5 Vdc @ 400 A continuous (3000 A
peak)
DC Output ON/OFF Buttons3. – Engages
and Disengages the dc output
receptacle.
60 Hz Input Circuit Breaker4. – Protects
the GPU from any power surges.
LED Charge Status Meter5. – Displays
current battery charge status when
pressed.
Air Intake Fan6. – Provides airow for
cooling internal components.
60 Hz 3-Phase AC Input Cable7. – Use for
60 Hz 3-Phase 208-240 Vac Input Power.
D8. VAM Interface Receptacle – Allows
direct connection of Tesla™ DVAM
(Digital Volt/Amp Meter).
4
1
6
2
7
8
5
3

TI4400 GPU-24 5
2
Product Overview
2.4 – General Specications
Electrical
AC Input Power:
Operates and charges from three phase 200-260 Vac 50/60 Hz•
40 amps @ 208 Vac•
Requires 60 amp service (contact Tesla Industries for receptacle information)•
Power Cell:
Dry, High Rate Discharge, Rechargeable , Maintenance-free•
DC Output Power:
1500 peak starting amps•
400 amps continuous @ 28.5 Vdc (when plugged into ac power) •
423 amp hours (11,912 watt hours) with three phase ac power•
23 amp hours (512 watt hours) of rechargeable battery power without three phase ac•
Recharge Rate From Full Discharge:
8 minutes @ 25°C•
Size:
50.23” L x 24.50” W x 16.28” H•
1275.80 mm x 622.30 mm x 413.50 mm•
Weight:
205 lbs (93 kg)•
Operating Temperature:
-40°C to +60°C (-40°F to 140°F) without ac power•
-40°C to +55°C (-40°F to 131°F) with ac power•
Storage Temperature:
-65°C to +105°C (-85°F to 221°F)•
Cell Capacity:
+40°C 110% ± 05%•
+25°C 100% ± 05%•
+00°C 80% ± 05%•
-20°C 65% ± 10%•
-40°C 50% ± 10%•

TI4400 GPU-24
6
2Product Overview
2.5 – Physical Dimensions
2.6 – Airow Ports
CAUTION Damage may occur if the unit’s air intake or outlet ports are obstructed.
Ensure that ports are clear at all times.
When the TI4400 GPU-24 is plugged into ac power, the internal cooling system will efciently regulate unit
temperature regardless of load. At room temperature (+77°F) the exhaust air will not exceed the ambient
temperature by more than 5°F. In more extreme temperatures (greater than 90°F) the exhaust air will not
exceed the ambient temperature by more than 10°F.
Figure 2.5.1 – TI4400 GPU-24 physical dimensions
Figure 2.6.1 – Air intake, exhaust ports and internal air circulation
50.23” (1275.80 mm)
24.50” (622.30 mm)
16.28” (413.50 mm)

TI4400 GPU-24 7
2
Product Overview
2.7 – Operating Positions
The TI4400 GPU-24 can be operated in both the horizontal (Figure 2.7.1) and vertical (Figure 2.7.2) positions
as shown. Make sure that the airow is not obstructed from air intake (gure 2.7.3) and outlet (Figure
2.7.4).
Figure 2.7.2: Vertical Position
Figure 2.7.1: Horizontal Position
Figure 2.7.3: Front Inlet Figure 2.7.4: Rear Outlet

TI4400 GPU-24
8
2Product Overview
Full Charge Half Charge No Charge
STATUSSTATUS STATUS
R
Y
G
0
1/2
OK
R
Y
G
0
1/2
OK
R
Y
G
0
1/2
OK
2.11 – “Push to Test” Button and LED Status Indicator
The “Push to Test” button indicates the capacity of the power cells without applying ac input power. The status
of the capacity lets the user know if there is enough power to perform another engine start. When the capacity is
low the unit should be connected to ac power to allow it to recharge.
Make sure that you wait at least 2 minutes after ac power is applied, or dc power is extracted from 1.
the unit, before you press the “Push to Test” button. This ensures a correct reading.
Without ac power input or dc power output, simply press the “Push to Test” button on the faceplate2.
and hold for approximately 2 to 3 seconds.
The LED bar graph should light up indicating the status of the power cells.3.
In addition, the fan(s) should start operating when the button is pressed. If you do not hear the4.
fan(s) running, stop pressing the button and check for any obstructions.
CAUTION
!Never press the “Push to Test” button while the unit is plugged into
aircraft, vehicle or ac power.
CAUTION
!
Never press the “Push to Test” button for more than 5 seconds. This
may cause a temperature sensor to temporarily disrupt “Push to
Test” function. (If this sensor is tripped, allow ten minutes for unit to
cool before operating “Push to Test” button.)
2.8 – “Push to Test” Button and LED Status Indicator
If unit is left charging after the
batteries are fully charged, the
unit will enter a standby mode.
The voltage will drop from
28.60 to 28.10 volts (±0.10).
When a load greater than 2
amps is applied, the unit will
return to normal operation.
NOTE
!
Figure 2.8.1 - “Push to Test” button

TI4400 GPU-24 9
2
Product Overview
2.9 – 60 Hz 3-Phase AC Input Circuit Breaker
The 3-phase 60Hz ac input circuit breaker is located at the center bottom of the GPU’s front panel. (See
Figures 4.4.1 and 4.4.2). It is also used as an On/Off Switch for powering the GPU. This switch controls AC
power input only. It does not control the dc output power.
Figure 2.9.2 - Three phase 60 Hz Input
Circuit Breaker
Figure 2.9.1 - Location of the 60Hz 3-Phase
AC Input Circuit Breaker (outlined in blue)
2.10 – DVAM Interface Receptacle
The DVAM (Digital Volt/Amp Meter) Interface Receptacle, located at the center bottom of the TI4400 GPU’s
front panel (see Figures 2.10.1 and 2.10.2), allows the user to measure the voltage and current at the DC
Output Receptacle using a Tesla™ TI3100A Digital Volt Amp Meter. Please contact the Tesla™ Customer
Service at [phone] to order.
Figure 2.10.1 - Location of DVAM Interface
Receptacle (outlined in blue)
Figure 2.10.2 - DVAM Interface Receptacle

TI4400 GPU-24
10
2Product Overview
This section covers normal procedures and steps necessary to ensure safe and ef cient operation of the
Refer to Section 7, PERFORMANCE DATA to determine the capability of the unit. Consideration must be given
charge (with or without ac power), and aircraft dc bus system inef ciency (voltage drops).
an ef cient engine start under speci c current load demands.
MINIMUM CHARGE
MINIMUM CHARGE
2.11 – DC Output “ON” and “OFF” Buttons
The DC output “ON” and “OFF” buttons are located directly above the 60 Hz AC Input Circuit Breaker (see
Figures 2.11.1 and 2.11.2 below). To prevent arcing while connecting or disconnecting DC power plugs, the
TI4400 GPU has been equipped with an internal contactor. The “ON” button engages this contactor for safe
transfer of power up to 3000 amps.
Figure 2.11.1 - Location of the DC Output On and
Off Buttons (outlined in blue)
Figure 2.11.2 - DC Output “On” and “Off”
Buttons
This section covers normal procedures and steps necessary to ensure safe and ef cient operation of the
Refer to Section 7, PERFORMANCE DATA to determine the capability of the unit. Consideration must be given
charge (with or without ac power), and aircraft dc bus system inef ciency (voltage drops).
an ef cient engine start under speci c current load demands.
MINIMUM CHARGE
MINIMUM CHARGE

TI4400 GPU-24 11
Section 3 – Operating Procedures
3.1 – Operating Procedures
This section covers normal procedures and steps necessary to ensure safe and ef cient operation of the
unit.
NOTE
!When not in use, the unit should always remain plugged into a suitable ac
power source to ensure operational readiness at all times.
NOTE
!If current demand exceeds 25 amps, converter output voltage will drop below
28.5 Vdc and two or more LED status indicator bars will illuminate. If all
LED status indicator bars illuminate, both the converter and power cells are
supplying 24 Vdc power output.
3.2 – General
The user should be well-versed in both pre-use and functional checks for correct operations of this unit.
Knowledge of the operating limits, restrictions, performance, unit capabilities and functions aids in correct
and safe operations. Compliance with the instructions in this manual affect operational safety as well as the
warranty of the unit.
3.3 – Operating Limits and Restrictions
The minimum, maximum and normal operating ranges result from careful engineering and evaluation of test
data. These limitations must be adhered to during all phases of operation.
3.4 – Performance
Refer to Section 7, PERFORMANCE DATA to determine the capability of the unit. Consideration must be given
to changes in performance resulting from variations in ambient temperature, mode of operation, state of
charge (with or without ac power), and aircraft dc bus system inef ciency (voltage drops).
3.5 – Engine Starting Power
The unit should always be charged above 80% prior to ground support engine starting. However, circumstances
may exist during use where unit recharge is not readily available and immediate external engine starting
power is required. The following provides minimum states of charge necessary to provide ample power for
an ef cient engine start under speci c current load demands.
MINIMUM CHARGE
MINIMUM CHARGE
This section covers normal procedures and steps necessary to ensure safe and ef cient operation of the
Refer to Section 7, PERFORMANCE DATA to determine the capability of the unit. Consideration must be given
charge (with or without ac power), and aircraft dc bus system inef ciency (voltage drops).
an ef cient engine start under speci c current load demands.
ENGINE START PEAK CURRENT Requirements MINIMUM CHARGE
Under 650 peak starting amps 0-50% charged
650 - 850 peak starting amps 50-60% charged
850 - 1000 peak starting amps 60-70% charged
1000 - 1200 peak starting amps 70-80% charged
1200 - 1500 peak starting amps 80-100% charged
MINIMUM CHARGE
If current demand exceeds 400 amps, converter output voltage will drop
below 28.5 Vdc and two or more LED status indicator bars will illuminate.
If all LED status indicator bars illuminate, both the converter and power cells
are supplying 24 Vdc power output.

TI4400 GPU-24
12
3Operating Procedures
Hot Soaked or Cold Soaked De nition
Simple terms: When a material is exposed to a change in temperature, its temperature will also change.
Some material changes temperature quickly, others slowly. If the ambient temperature changes and is then
held constant, the materials temperature will also change until its temperature stabilizes. Once the material
temperature has stabilized, it is considered “soaked”.
Example: A unit is moved from the cool shade into the hot sun. That unit’s temperature will increase until it
stabilizes. Once stabilized, the unit would be considered “hot soaked”.
NOTE
!
The unit’s temperature switch automatically disables ac power functions
when the internal temperature is above 150°F (65°C). This protects the unit
from overheating and damage. If the unit shuts down, move the unit into a
cooler climate, such as shade or air conditioning when possible. Perform a
full function test prior to use after the unit has been allowed to cool.
3.6 – Temperature Speci cations
Cold/Hot Soaked Temperature
Exposing the unit for one (1) hour or more to the ambient temperature establishes the unit’s cold/hot
soaked stabilization temperature. If the unit’s cold/hot soaked temperature is outside the normal operating
temperature range, the unit must be stabilized prior to operation. For COLD SOAKED temperature stabilization,
the unit must be placed in an environment with a temperature above +10°C (+41°F) for 3 hours or a
temperature above +20°C (+68°F) for 2 hours. For HOT SOAKED temperature stabilization, the unit must
be placed in an environment with a temperature below +38°C (+100°F) for 1 hour.
120%
100%
80%
60%
40%
+40°C +25°C +0°C -20°C -40°C
Ambient
Temperature
+40°C (+104°F)
+25°C (+77°F)
+0°C (+32°F)
-20°C (-4°F)
-40°C (-40°F)
110% ±5%
100% ±5%
80% ±5%
65% ±10%
50% ±10%
Percentage of
Cell Capacity
Figure 3.6.1 – Output power capability versus ambient temperature

TI4400 GPU-24 13
3
Operating Procedures
3.7 – Environmental
If the unit is exposed to moisture, preventive measures and precautions shall be taken to:
A. Prevent accumulation of moisture on ac and dc connectors/receptacles
B. Minimize moisture entering forward inlet and aft outlet cooling fan vent ports
Unit inlet and outlet vent ports shall be covered from exposure. Unit shall be kept horizontal.
Recommendations include a Protective Rain Cover to guard the unit from moisture (see Section 8). The limits
and operational constraints listed below shall apply for the following environmental (weather) conditions:
WARNING Operating any electrical equipment in the presence of moisture creates
possible safety hazards and/or potential for equipment damage. Every
effort has been made, within the scope of existing technology to prevent
foreseeable safety hazards and make the unit moisture resistant to prevent
damage or failure.
Conditions With
Raincover Without Raincover
Heavy or steady rain:
Precipitation falling with an intensity in excess of 0.30 inch
(0.76 cm) or continuously between 0.30 and 0.10 inch per hour.
OK OPERATION NOT RECOMMENDED
Light rain, drizzle or sleet:
Precipitation falling on a continuous basis between 0.10 inch
and less than 1/50 inch (0.5 mm) per hour
OK DC OPERATIONS ONLY
Heavy or steady snow:
Generally meaning an accumulation between 4 inches and less
than 1 inch in a 12 hour period.
OK OPERATION NOT RECOMMENDED
Light snow:
Snow falling intermediately with little or no accumulation.
OK DC OPERATIONS ONLY
Fog: OK OK
If the unit is exposed to signi cant moisture, preventive measures and precautions shall be taken to:
B. Minimize moisture entering forward inlet and outlet cooling fan vent ports
Figure 3.6.1 – TI4400 GPU-24 with TI7000-084 Protective Rain Cover