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Copyright © 2014 Delmar, Cengage Learning Truck Trailer Refrigeration Electrical Components Instructor Name: (Your Name) 16 CHAPTER.

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Presentation on theme: "Copyright © 2014 Delmar, Cengage Learning Truck Trailer Refrigeration Electrical Components Instructor Name: (Your Name) 16 CHAPTER."— Presentation transcript:

1 Copyright © 2014 Delmar, Cengage Learning Truck Trailer Refrigeration Electrical Components Instructor Name: (Your Name) 16 CHAPTER

2 Copyright © 2014 Delmar, Cengage Learning Learning Objectives  Describe the construction of storage batteries  Work safely around storage batteries  Explain the two different ways in which batteries may be shipped from the manufacturer  Describe the three different types of batteries used today and how maintenance is performed on them  Explain how batteries are rated  Describe storage procedures for batteries  Explain testing procedure to ensure batteries can perform to rated performance level

3 Copyright © 2014 Delmar, Cengage Learning Learning Objectives (continued)  Describe how a battery should be charged and list the steps involved in jump-starting a unit with a low battery  List the steps in removing and replacing a battery  Explain the function of the charging system  List the major components of a typical alternator and the function of the parts  Explain the function of a voltage regulator  Describe the steps of an alternator output test

4 Copyright © 2014 Delmar, Cengage Learning Learning Objectives (continued)  List the steps involved in removing and replacing an alternator  Describe the two styles of starters used in the transportation refrigeration industry  Explain the purpose of an overrunning clutch  Describe the steps involved in performing a starter test  Explain the purpose of the various truck refrigeration safety switches

5 Copyright © 2014 Delmar, Cengage Learning Battery Construction  Case filled with diluted solution of sulfuric acid and water  Positive and negative electrodes in the form of plates  Plates composed of lead or lead derived material  Batteries are divided into several cells, 6 cells for a 12 volt battery

6 Copyright © 2014 Delmar, Cengage Learning Typical Battery

7 Copyright © 2014 Delmar, Cengage Learning Cell Operation When two dissimilar metals are placed in an acid bath, an electrical potential is produced across the poles Voltage is produced due to a reaction between the plates and the electrolyte The positive plate is composed of lead peroxide The negative plate is composed of sponge lead Electrolyte is a solution of water and sulfuric acid

8 Copyright © 2014 Delmar, Cengage Learning Cell Operation (continued)  Six cell elements in a 12 volt battery  Each cell produces approximately 2.1 volts regardless of size and number of plates  Cells are connected in series to produce 12.6 volts

9 Copyright © 2014 Delmar, Cengage Learning Single Battery Cell

10 Copyright © 2014 Delmar, Cengage Learning Battery With Six Cells

11 Copyright © 2014 Delmar, Cengage Learning Battery Safety  Keep flames and sparks away form batteries, do not smoke near batteries  Wear eye protection and rubber gloves to protect from chemical burns  Never connect or disconnect live circuits. Always turn off unit, battery charger or tester when attaching or removing leads  Batteries should always be installed in a vented battery box to vent hydrogen gas while charging

12 Copyright © 2014 Delmar, Cengage Learning Battery Safety (continued)  Work in a well vented area when charging batteries  Always keep the battery upright to prevent spilling electrolyte  Never work alone on batteries, in case of accident

13 Copyright © 2014 Delmar, Cengage Learning CAUTION Battery electrolyte contains sulfuric acid, which can cause severe personal injuries (burns) and damage to clothing and equipment. If electrolyte is spilled or splashed on a person’s body or clothing, it must be immediately neutralized by washing with a solution of baking soda and water. The solution should be 0.25 pounds baking soda to 1 quart of water. Electrolyte splashed into the eyes is extremely hazardous. The eyes should be immediately held open and flushed with cool clean water for about 5 minutes, then seek medical treatment at once.

14 Copyright © 2014 Delmar, Cengage Learning Battery Types; Conventional  Require the most maintenance  Water in electrolyte turns to a gas and must be replenished  Use only distilled water when filling a battery  Water level should be no higher than 1/8 ” (3.2 mm) below vent well  Damage can occur if electrolyte level drops below top of cell plates  Over filling can weaken electrolyte solution and battery

15 Copyright © 2014 Delmar, Cengage Learning Battery Types; Conventional (continued)  Vaporized electrolyte can condense on top of case and discharge battery  Vaporized electrolyte can condense on top of case and corrode terminal and cables  Conventional batteries are easily overcharged  Conventional batteries perform well in a deep cycle application

16 Copyright © 2014 Delmar, Cengage Learning Correct Electrolyte Level

17 Copyright © 2014 Delmar, Cengage Learning Low Maintenance Batteries  Less maintenance then conventional batteries  Less electrolyte gasification  Less corrosion of terminals  More resilient to over charging  Shorter life in a deep cycle application

18 Copyright © 2014 Delmar, Cengage Learning Maintenance Free Batteries  Designed to not require electrolyte replenishment under normal operating conditions  Terminal and cable ends almost maintenance free  Generally require higher voltage regulator settings then conventional and low maintenance batteries

19 Copyright © 2014 Delmar, Cengage Learning Battery Ratings CCA  Performance rated by their cold cranking amps (CCA) designation  Load in amperes a battery can sustain for 30 0 ⁰ F (-17.8 ⁰ C) and not fall below 1.2 v per cell or 7.2 v on a 12 v battery  CCA indicates how much power a battery can deliver in extremely cold conditions

20 Copyright © 2014 Delmar, Cengage Learning Cold Weather Effects on Battery

21 Copyright © 2014 Delmar, Cengage Learning Battery Ratings; Reserve Capacity  The number of minutes a new fully charged battery at 80 ⁰ F (26.6 ⁰ C) can sustain a load at 25 amperes before battery voltage drops to 1.75 V per cell or 10.5 V for a 12 V battery.  Reserve capacity indicates how long a battery can provide enough power to keep ignition, head and tail lights, windshield wipers, and heater operating if charging system fails

22 Copyright © 2014 Delmar, Cengage Learning Battery Rating; BCI Number  Battery Council International (BCI) a number indicates batteries physical dimensions  BCI number indicates the height, width, and length  BCI number is no indication of the batteries performance capacity  A batteries performance characteristic is determined by internal components

23 Copyright © 2014 Delmar, Cengage Learning BCI Battery Dimensions

24 Copyright © 2014 Delmar, Cengage Learning Battery Maintenance 1.Check for loose terminals 2.Check for cracked or broken case 3.If case is broken replace immediately 4.Inspect case for dirt, moisture, and corrosion 5.Clean case and terminals with baking soda 6.Battery cable should be checked for cleanliness and tightness 7.Check electrolyte level, add water if low Note: Even maintenance free batteries electrolyte levels should be checked monthly

25 Copyright © 2014 Delmar, Cengage Learning Hydrometer Testing  Hydrometer tests the state of charge by measuring the specific gravity of electrolyte  A fully charged battery will have a specific gravity of at 80 ⁰ F (26.7 ⁰ C)  A hydrometer must be temperature compensated, add.004 for every 10 ⁰ above 80 ⁰ F and subtract.004 for every 10 ⁰ below 80 ⁰ F

26 Copyright © 2014 Delmar, Cengage Learning Hydrometer Reading

27 Copyright © 2014 Delmar, Cengage Learning Refractometer Testing  No temperature compensation needed  Wear eye protection when using refractometer  Extract a drop of electrolyte, place on lens of refractometer  Hold meter up to light and view readings Electrolyte Reading Reading% Charge

28 Copyright © 2014 Delmar, Cengage Learning Open Circuit Voltage Test  Determines battery state of charge  Performed when battery is at rest, no load  Remove surface charge prior to test Meter ReadingBattery Condition 12.66Fully Charged % Charge % Charge % Charge

29 Copyright © 2014 Delmar, Cengage Learning Battery Load Test  Load test gives true measurement of a batteries ability to perform  Battery must be fully charged  Load to 50% of rated CCA  Hold load for 15 seconds  Battery voltage should not drop below 9.6V at 70 ⁰F (21 ⁰ C )  Replace battery if it falls below minimum specifications

30 Copyright © 2014 Delmar, Cengage Learning Jump Starting  Connect to positive terminal of stalled battery  Connect to positive terminal of jumper battery  Connect to negative terminal of jumper battery  Connect to good chassis ground on stalled vehicle away form batteries  Disconnect jump cable exact reverse order used to connect them

31 Copyright © 2014 Delmar, Cengage Learning Alternator Components Stator  Three individual windings in a ring made of iron  Electrical impulses occur at different times to produce three phase current Rotor  Rotating magnet that spins inside the stator  Wire coil between two interlocking iron sections mounted on a shaft  Each lobe is a north or south magnetic pole  Rotor is magnetized only when current is applied through slip rings and brushes

32 Copyright © 2014 Delmar, Cengage Learning Alternator

33 Copyright © 2014 Delmar, Cengage Learning Rotor and Stator

34 Copyright © 2014 Delmar, Cengage Learning Alternator Components (continued) Rectifier Diodes  Alternator produces alternating current  Rectifier diodes changes alternating current to direct current  Field diodes are used to separate field circuit from rectifier circuit Voltage Regulator  Voltage regulator performs two tasks  Regulator excites the field coil  Regulator regulates the output voltage of the alternator to a set safe value during charging

35 Copyright © 2014 Delmar, Cengage Learning Alternator Output Test  Output test checks alternators ability to deliver rated output of voltage and current  Performed if unit is over or under charging  Run unit at high speed  Adjust load to highest current with out dropping voltage below 12 volts  Read ammeter, reading should be with in 10% of the alternators rated output capacity  Always follow the load tester manufactures instructions when testing an alternators output

36 Copyright © 2014 Delmar, Cengage Learning Alternator Removal and Installation  Always disconnect battery first  Identify positive an negative terminal before hooking up, reversed polarity can destroy rectifier diodes  Alternator belt should wrap around pulley a minimum of 100 degrees and be 90 degrees with face of pulley  Check belt tension by consulting the maintenance manual  If charging the battery on the unit, disconnect the positive cable to prevent damage to the alternator or voltage regulator

37 Copyright © 2014 Delmar, Cengage Learning Alternator Installation Belt to Pulley AlignmentBelt Engagement in Pulley

38 Copyright © 2014 Delmar, Cengage Learning Starters  Two styles used in transportation refrigeration, conventional and gear reduction  Conventional starter pinion gear mounted on the motor armature  Conventional starter uses solenoid to pull plunger and lever to move pinion gear into mesh with ring gear  Gear reduction starter uses smaller high speed motor  Gear reduction pinion gear turn at 1/4 to 1/3 motor speed  Gear reduction solenoid acts directly on reduction gear and pinion gear  Overrunning clutch prevent damage to pinion gear once engine starts

39 Copyright © 2014 Delmar, Cengage Learning Conventional Starter

40 Copyright © 2014 Delmar, Cengage Learning Gear Reduction Starter

41 Copyright © 2014 Delmar, Cengage Learning Overrunning Clutch

42 Copyright © 2014 Delmar, Cengage Learning Starter Testing  Starter amp draw test ensures starter is in good condition  Starter amp draw test also test condition of batteries  Ensure batteries are in good condition and at a minimum of 50% charge  Use a suitable amp meter on the batteries  Disable the engine from starting during test  Crank engine and watch current draw  Cranking speed should be normal and current draw should not exceed manufacturers specification  Always follow the manufacturers recommendations for this test

43 Copyright © 2014 Delmar, Cengage Learning Safety Switches  Low oil pressure cut out switch protects engine in the event of low or loss of oil  Installed in the oil galley of the engine  Engine shuts down if oil pressure drops below 15 psi  High engine coolant temperature switch is normally located in the cylinder head water passages  If engine coolant temperature rises to a preset point the bimetal switch contacts open circuit causing engine to shut down  Newer style can be an electronic switch that sends signal to the engines microprocessor

44 Copyright © 2014 Delmar, Cengage Learning Low Oil Pressure and High Engine Temperature Switches

45 Copyright © 2014 Delmar, Cengage Learning Safety Switches (continued)  High compressor discharge switch may be mounted in compressor cylinder head, discharge manifold, or line between compressor and condenser  High compressor switch will shut down engine if a preset discharge pressure is reached  Low compressor oil pressure switch shuts unit down in the event of loss of oil pressure in the compressor

46 Copyright © 2014 Delmar, Cengage Learning High Pressure Cut Off Switch

47 Copyright © 2014 Delmar, Cengage Learning Summary  Transport refrigeration equipment uses 12 automotive type storage batteries  Batteries work on principle that when two dissimilar metals in acid bath, and electrical potential is produced  Each cell of a battery produces 2.1 volt  12 V batteries use 6 cells connected in series  Always follow safety precautions when working around batteries  Batteries may be shipped from manufacturer as wet charged or dry charged

48 Copyright © 2014 Delmar, Cengage Learning Summary (continued)  There are three classifications of batteries, conventional, low maintenance, and maintenance free  Batteries are rated by BCI rating, CCA rating, or reserve capacity  Batteries should be stored in a clean dry environment between 50 ⁰ F and 60 ⁰ F (10 ⁰ C and 16 ⁰ C)  Batteries can be tested by open circuit test, specific gravity and load test  If a battery has been discharged fast it should be charged fast, if it has been discharged slow it should be charged slow

49 Copyright © 2014 Delmar, Cengage Learning Summary (continued)  Jump starting a vehicle is performed when the units battery is low and the unit must run. The battery will require maintenance as soon as possible  The charging system is responsible for recharging battery once unit is running and providing current for system loads  The rectifier converts alternating current to direct current  The voltage regulator controls alternator output voltage within a safe limit, as specified by equipment manufacture

50 Copyright © 2014 Delmar, Cengage Learning Summary (continued)  An alternator output test confirms how many amps the alternator can produce when fully loaded, in comparison to rated output  Starters for refrigeration units fall into two different categories, conventional starters and gear reduction starters  An overrunning clutch protects the starter from excessive engine rpm by disengaging the pinion gear from the armature of the starter

51 Copyright © 2014 Delmar, Cengage Learning Summary (continued)  Starters are tested by measuring the number of amps they draw when starting the engine, in comparison to the starters rated draw  Safety switches protect people from any personal injury as well as protect the unit from physical damage caused by running a unit under abnormal conditions


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