Tesla TI4676 MPU User manual

Tesla™TI4676 MPU
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

TI4676 MPU-24 11-30-20
NOTE: All users must read this entire manual prior
to operating the TI4676 MPU-24.
The TI4676 MPU-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 MPU 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.
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 © 2020 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 2222 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.
For expanded detailed info, download the PDF online at...
http://www.teslaind.com/PDF/chart/Tesla-Safety-Data-Sheet.pdf
or go to
http://www.teslaind.com/support-manuals.php
and click on
“Battery Safety Data Sheet” link under “Battery Info” heading.
or use the QR Code to the right.

TI4676 MPU-24
Table of Contents
Section 1 – Safety Review 1-2
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 3-7
2.1 – Introduction 3
2.2 – Indication of Terms: Shall, Should, May 3
2.3 – Front Panel Overview 4
2.4 – General Specications 5
2.5 – Physical Dimensions 6
2.6 – Airow Ports 6
2.7 – “Press for Capacity” button and LED Status Indicator 7
2.8 – Maintenance Check 8
2.9 – Pre-Installation Procedures 8
Section 3 – Operating Procedures 9-17
3.1 – Operating Procedures 9
3.2 – General 9
3.3 – Operating Limits and Restrictions 9
3.4 – Performance 9
3.5 – Engine Starting Power 9
3.6 – Temperature Specications 10
3.7 – Environmental 11
3.8 – Normal Function Test Procedures 12-13
3.9 – Regulated 28.5 VDC Ground Power 14
3.10 – Regulated AC Power 14-15
3.11 – AC Input Circuit Breaker 16
3.12 – Universal AC Input Line Cord 16
3.13 –Charging the Unit 17

TI4676 MPU-24
Section 4 – Post Operation 18-19
4.1 – General 18
4.2 – After Use 18
4.3 – Power Cell Recharge 18-19
Section 5 – Unit Care and Maintenance 20-21
5.1 – Unit Care 20
5.2 – Unit Servicing 21
5.3 – Packaging and Shipping 21
Section 6 – Troubleshooting FAQ 22-23
6.1 – Frequently Asked Questions 22-23
6.2 – Basic Usage / Operation Questions 23
Section 7 – Performance Data 25
7.1 – Purpose 25
7.2 – General 25
7.3 – Data Basis 25
7.4 – Specic Conditions 25
7.5 – General Conditions 25
7.6 – Temperature Conversion Chart 26
7.7 – Output Voltage 27
7.8 – Maximum Output Current 27
Section 8 – Optional Accessories 28
8.1 – Shipping Case 28
8.2 – Tesla™ AC Line Cords 28
8.3 – Tesla™ AC Universal Line Cords 29
Appendix A 30-34
Repair Request Form 35

TI4676 MPU-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

TI4676 MPU-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
!
!
!

TI4676 MPU-24
2
1Safety Review
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.
1.3 – Hazards
WARNING Shock Hazard Potential
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.
CAUTION Unit Damage 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.
Figure 1.3.1 – Proper Ground
Grounded Plug with Grounding Pin
Figure 1.3.2 – Proper Ground
Adapter with Grounding Mechanism
(Secured to Outlet)
Figure 1.3.3 – Improper Ground
Plug with No Grounding Pin
The use of unapproved ac power will damage the unit. Check the
Input Voltage Selector Switch window (outlined in blue) to ensure
the switch setting (115V or 230V) matches the ac power source
(hangar wall,  ight line ac power) prior to connecting the unit for
recharging.

TI4676 MPU-24 3
Section 2 – Product Overview
2.1 – Introduction
This manual contains the complete operating instructions and procedures for the TI4676 Micro Power Unit
(MPU). The TI4676 MPU-24 provides dc electrical ground power for onboard battery. The unit is designed to
provide 24 volt DC electrical power output for aircraft engine starting and 24 or 28.5 volts dc electrical support
for ground maintenance, avionics/electrical trouble shooting and testing. The observance of procedures,
limitations and performance criteria ensures peak operating efciency and maximizes operational capabilities
and life of the TI4676 MPU-24.
Figure 2.1.1 – TI4676 MPU-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.

TI4676 MPU-24
4
2Product Overview
24 Vdc Output Connector1. – Provides 24 Vdc to 28.5 Vdc @ 10 A
continuous.
24 Vdc Capacity Meter2. – Indicates the 24V battery charge state/power
output status.
“Press for Capacity” Button3. – Displays current battery charge state
when pressed.
AC Input Circuit Breaker4. – Trips if over-current fault condition occurs.
AC Input Connector5. – Connects to Single Phase 100-260 Vac line
voltage.
2.3 – Front Panel Overview
1
2
3
4
5

TI4676 MPU-24 5
2
Product Overview
2.4 – General Specications
Electrical
AC Input:
Operates and charges from Single Phase 100-260 Vac, 45-450 Hz•
5.5 amps @ 120 Vac•
2.75 amps @ 240 Vac•
Power Cell:
Dry, High Rate Discharge, Rechargeable , Maintenance-free•
DC Output:
1500 peak starting amps•
10 amps continuous @ 28.5 Vdc - 285 Watts (when plugged into ac power)•
33 amp hours (797 watt hours) with 100-260 Vac power•
23 amp hours (512 watt hours) of rechargeable battery power without 100-260 Vac•
Rechargeable Rate:
143 minutes (from full discharge) @ 25°C•
Size:
10.85” long x 9.68” wide x 9.43” high•
275.6 mm x 245.87 mm x 239.52 mm•
Weight
53 lbs (24 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%•

TI4676 MPU-24
6
2Product Overview
9.43 [239.52]
10.85 [275.6]
9.68 [245.87]
2.5 – Physical Dimensions
2.6 – Airow Ports
CAUTION Damage may occur if the TI4676 MPU-24’s air intake or outlet ports are
obstructed. Ensure that ports are clear at all times.
The internal cooling system efciently regulates unit temperature regardless of load when plugged into ac
power. 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.
Make sure that the airow is not obstructed from air intake (Figure 2.6.1) and outlet (Figure 2.6.2).
Front View Top View Side View
Figure 2.6.1 Side Inlet Figure 2.6.2 Top Outlet

TI4676 MPU-24 7
2
Product Overview
MPU
2.8 – “Press for Capacity” Button and LED Status Indicator
The “Press for Capacity” 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 from1.
the unit, before you press the “
Press for Capacity ” 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 “Press for Capacity” button while the unit is
plugged into aircraft, vehicle or ac power.
CAUTION
!
Never press the “Press for Capacity” button for more than 5 seconds.
This may cause a temperature sensor to temporarily disrupt “Press
for Capacity” function. (If this sensor is tripped, allow ten minutes for
unit to cool before operating “Press for Capacity” button.)
Full Charge Half Charge No Charge
2.7 – “Press for Capacity” Button and LED Status Indicator
Figure 2.7.1 “Push to Test” button location
(outlined in blue)
Figure 2.7.2 Pushing to Test

TI4676 MPU-24
8
2Product Overview
2.8 – Maintenance Check
Check the unit for dents, punctures, case distortion or misalignment, and cracked or loose connectors. Check
cables for cuts, chang or evidence of crushing. Check connectors for cracks, cuts, distortion, excessive
wear, broken or loose fasteners, and cables or strain relieves. If no external damage is evident, proceed to
next step. Otherwise contact Tesla™ for further instructions.
2.9 – Pre-Installation Procedures
Removing Original Battery
Follow the aircraft’s operator manual procedures to remove and dispose of the original aircraft battery
properly and safely. Once the original battery has been removed from the battery compartment, proceed to
the next step.
Check Unit Charge State
Before installing the unit into the aircraft, make sure the unit is fully charged. Remove the ac line cord from
the ac input connector and wait two minutes. Then, push the “Press for Capacity” button to verify that the
power cells are fully charged. Under a full charge the Capacity Meter will show a single green LED.
!If the unit is not fully charged after 143 minutes, the power cells may need
to be replaced. Return the unit to Tesla™ Industries for evaluation and
maintenance.
NOTE

TI4676 MPU-24 9
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.
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
ENGINE START PEAK CURRENT Requirements MINIMUM CHARGE
Under 1200 peak starting amps 0-40% charged
1200 - 1500 peak starting amps 40-50% charged
1500 - 1800 peak starting amps 50-60% charged
1800 - 2100 peak starting amps 60-70% charged
2100 - 2400 peak starting amps 70-80% charged
2400 - 3000 peak starting amps 80-100% charged
If current demand exceeds 10 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.

TI4676 MPU-24
10
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

TI4676 MPU-24 11
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
3.7 – Environmental
If the unit is exposed to signi cant 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 outlet cooling fan vent ports
When not in use, unit inlet and outlet vent ports shall be covered from exposure. Unit shall be kept
horizontal.
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.

TI4676 MPU-24
12
3Operating Procedures
3.8 – Normal Function Test Procedures
This section involves “normal function” test procedures, and includes steps necessary to ensure that the
TI4676 MPU-24 is operating within specied para meters prior to use. A digital multimeter (an example is
shown in Figure 3.8.1) capable of measuring dc and ac voltage and resistance will be required to perform
some of the tests. These functional test procedures should become routine.
Figure 3.8.1 – Digital Multimeter
Figure 3.8.2 – AC Input Connector wiring diagram
AC Hot
Pin “K”
AC Neutral
Pin “M”
AC Ground
Pins “J,L”
AC Input Connector

TI4676 MPU-24 13
3
Operating Procedures
6. Move the positive probe to
the dc positive post.
5. Move the positive probe to
the dc negative post.
4. Move the positive probe to
the fastener
1. Place the negative probe on
the ac ground probe and the
positive probe on the case.
2. Move the positive probe to
the dc positive post. 3. Move the positive probe to
the dc negative post.
Check DC Voltage Reading at DC Receptacle Terminals
To verify that the power cells are fully charged, set the digital
mulitmeter to measure dc voltage. Place the positive probe (red)
on the positive post of the dc output connector, as shown in Figure
3.8.3. Next, place the negative probe on the negative post. The
multimeter display should read approximately 28.5 Vdc (± 0.5 Vdc)
when power cells are fully charged and the unit is plugged into an
ac power source. When the unit is not plugged into an ac power
power source, the mulitmeter display should read 25.5 Vdc.
Figure 3.8.3 – Testing DC Receptacle
Check Unit Internal Resistance (Test for Shorts)
It is essential to test for shorts to detect any problems with the unit. First, set the multimeter to the “resistance”.
Next, test to see if both terminals are isolated from the chassis ground and the line ground using the steps
below. In steps 2, 3, 5 and 6, a reading of greater than 10 MΩ will assure no shorts exist. In steps 1 and 4,
the multimeter should read less then 1 Ω.