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Engine starting systems final2
- 1. Engine Starting Systems Technical Training
- 2. Objectives: • Understand a basic electric starting circuit • Identify and explain the functions of starting system components • Properly identify common starting system malfunctions
- 4. Battery • Supply electrical power to starter
- 6. Battery Checks • Corrosion, dirt • Cracks, or damaged case • Leakage
- 8. Starter Switch • Provides driver’s control for the starter.
- 9. Starter • Cranks the engine over to start the engine.
- 10. Starter • • • • • • • Specifications 50MT: Engine Type/Size: Diesel up to 29.5 L / 1800 cu in System Voltage: 12, 24, 32, 64 Volts Rotation: Clockwise or Counterclockwise Output: 10.7, 12, 16, 17.4 HP, 8.5, 9, 12, 13kW Standard Mountings: SAE #3 Standard Pinions: 11-Tooth/6-8 Pitch, 12-Tooth/8-10 Pitch, 12Tooth/Module 3 • Weight: 79 lbs (35.8 kg) • Drive Design: Rotatable drive housing, positive engagement, rubber shock absorber • Overcrank protection: None
- 11. Wiring • Connects all of the components together to allow electron flow.
- 12. Wiring • Conductors Conducts Electron flow • Insulators Prevents Electron Flow
- 13. Visual Checks • Missing insulation • Broken wires • Burning smell
- 14. Visual Checks
- 15. Safety
- 17. Neutral Safety Switch • Allows starting ONLY when bus is in neutral.
- 18. Starter Relay
- 19. Starter Relay • A relay is a control device that allows a small circuit to control a large circuit.
- 20. No Start Malfunctions • Cranks, no start
- 21. No Start Malfunctions • Clicks, no start
- 22. No Start Malfunctions • No click, no start • Ensure transmission is in neutral!
- 23. Remember YOU are our eyes and ears! • The better your description is of what is happening, the faster our mechanics can properly diagnose the problem.
- 24. Questions
- 25. Good Luck Thank you for your time! Technical Training
Notas del editor
- Good morning, Im Ken Waters with RTD, I will be your instructor for basic starting systems
- Our goal is that in the next 10 minutes, you willbe able to Understand a basic electric starting circuit (CLICK)identify and explain the functions of starting system components (CLICK)And be able to properly identify common starting system malfunctions we see here at RTD.
- Now here’s our basic starter circuit. We’ll brake this down to each of it’s components so you know their names, and what their functions are for starting the bus.Battery,Starter Switch,Starter,Wiring which connects it all togetherThere’s a couple more components we’ll add to this, but for right now this is all we need to worry about
- So, lets start with where the power comes from. This is what a typical battery compartment looks like in our bus fleet. It’s a 24 volt power supply because that’s what is required to start and run most of our buses. For purposes of this class, It’s sole job is to (CLICK)supply electrical power to our starter. We get 24 volts out of this setup because we have two, 12 volt batteries “in series” to obtain 24 volts.
- Now, what that means is that the batteries are connected in this configuration here on the right,,, with positive post to negative post,,, just like stacking batteries in a flashlight. When we do this with (2) 12 volt batteries, we get a 24 volt power supply
- Now, when you’re performing an inspection of the battery compartment, here are some of the problems you’ll want to look for.Corrosion found anywhere on the battery or its cables. Corrosion is that white chalky looking substance. Dirt on top of the battery case can also cause problems and needs to be removed. (CLICK)Cracks or damage to the case. You may also notice a strong chemical smell that smells like rotten eggs coming out of the battery compartment. (CLICK)Any kind of leaks from the battery or it’s vents is also an indication of a problem.If you DO find any of these problems, or anything else that’s out of the norm, go ahead and write it up in the driver’s book so our running repair can address these items before they turn into major problems, or even worse, cause a roadcall.
- And DO remember, unless you have protective gloves on, these are VISUAL checks ONLY for the battery. The fluid in the battery is made up of sulfuric acid. The powdery corrosion we looked earlier has a lot of sulfuric acid in it, and if you do touch this, the oils & sweat on your hand will reactivate it, and it WILL start burning. So, again, no need to be getting any of this nasty stuff on your skin.
- A little farther down from our battery in the circuit, is going to be our starter switch. What the starter switch does is (CLICK) provide driver’s control for the starter. When the button is pushed, the control circuit is completed, and power is supplied to the starter on the control circuit. When the button is released, power is removed from the starter and cranking ceases. Again if you find anything wrong with the switch, ie. Loose in the dash, sticking, coffee oozes out when you push it, whatever,,,, just write it up in the driver’s book so we can get that addressed as well.
- And here’s our starter. This particular starter is for our detroit diesels, but most starters function and look the same.The one and only job thestarter has,, is to (CLICK) crank the engine over,and start the engine.
- Here’s the spec’s for our starter. The only spec that you need to be concerned about is the last one… It IS possible with this starter to crank an engine over constantly,, which can overheat the starter and damage other components real quick. It should take no longer than 5 seconds of crank time to start the engine. If it does, then that’s because something’s gone wrong., and no extra amount of crank time is going to bring that bus back to life.
- Now we need to take a look at the wiring…. It’s job is to (CLICK) connect all of our components together which allows electron flow. Without the wiring, nothing would work because there ALWAYS has to be a complete “closed” circuit for anything electrical to operate. Any time there is an open, like when the starter switch is not pressed, there is no electron flow, and nothing happens.
- Wiring is made up of copper, and rubber insulation. The copper wiring (CLICK) conducts electron flow, and the rubber insulation (CLICK) prevents electron flow.You see, electrons are rather lazy, and are always trying to take the “path of least resistance” You’ve probably heard of that expression before. The insulation prevents electrons from leaving our circuit, and performing the job we need them to do, ie. Start the engine.
- If you happen to see wiring that’smissing insulation, (CLICK) broken wires, or if you notice a (CLICK) burning smell,,,,
- WRITE IT UP! And again, if you find a problem with anything that we talked about (CLICK) or anything else, just remember to write it up also in the driver’s book so we can get it fixed.
- Now since the experience of losing control of one of our buses is not an experience ANYONE should have to go thru, there is also a safety feature included to our starter circuit to help prevent the coach from rolling forward or backwards during startup.
- Now, back to our basic starter circuit, if we install a neutral safety switch to our circuit, (CLICK) we can ensure that the transmission IS in neutral when the engine is started. If the bus is NOT in neutral, then there is no way for the driver to be able to crank the engine over, and possibly lose control of the coach.The neutral safety switch here serves as an “open” on the control side of our circuit to disable starting. What it does, is it prevents the bus from jolting forward or reverse right after the engine is started.
- The switch can be found in different locations depending on the bus, but regardless of where it is, it’s function on all of the coaches is the same. (CLICK) To allow starting ONLY when the bus is in neutral.
- Now since copper wiring is expensive, and heavy, most customer’s in this day and age are interested in better fuel economy and cheaper products. So manufacturer came up with a way to lower costs and weight by reducing the amount of copper wire installed on the coach. The way they accomplished this was to add a relay to our starter circuit. (CLICK) All a relay is, is a device that allows a small circuit to control a large circuit. What it allows us to do, is to be able to use smaller diameter wiring on our coaches, specifically for this contol circuit.
- Here’s some starter relays that we currently utilize in our fleet.And remember, all a relay is,,,,,, (CLICK) is a control device that allows a small circuit to control a large circuit.The purpose for relays is to save weight, and lower costs.
- Now let’s take a look at some common starter system malfunctions we see here at RTD. Now we currently have SEVERAL ways of describing this,,,Bus don’t run, bus broken, bus don’t start, dead bus…So, in an effort to effectively communicate with our running repair, this condition is now known as: (CLICK)Cranks, no startWhat this does,,, is it give’s our mechanics specific information about what’s going on with the bus. And actually, this ISN’T a problem with the starter system at all. Remember, the starter’s ONLY job is to crank the engine over. If you see this, PLEASE don’t continue to crank it constantly, all that does is drain batteries and damage equipment. Try 2-3 more times, at no more than 5 seconds of crank time to see if it will start, if it won’t, then it’s time to let running repair know that the bus, “CRANKS, BUT DOES NOT START”
- So, letstake a look at another one. Since this one clicks, no start, lets just call it that. (CLICK) Simple to remember, right?Now this one IS most likely going to be due to a malfunction with our starting system. Sometimes you wont even get a click, or maybe a rapid clicking. Typically on these scenarios, the batteries are discharged to the point where there’s not enough current to crank the engine over, you may also notice the lights in the coach are dim or flickering.Again, try it 2-3 more times, and if u get no where, let running repair know that the bus “CLICKS, BUT DOES NOT START”
- One thing to keep in mind if you don’t hear anything when you try and start the bus. (CLICK) That you may have the bus IN neutral. And what component in our starter system could cause this?Neutral safety switch, right!So if you see this one, just make sure you (CLICK) HAVE the bus IN neutral.I can’t tell you how many service calls I’ve been on where this WAS the reason the bus wouldn’t start.
- Just remember YOU are running repair’s eyes and ears! Sometimes these problems you see are intermittent, and can be difficult to duplicate for diagnosis,,,, (click) So The better your description is of what’s happening, the faster running repair can properly diagnose & fix the problem.. And most importantly,,, we get the bus back out on the road again.
- Quick review,Anyone have questions on our basic starter circuit,Can everyone identify our 6 starting system components battery wiring starter switch starter neutral safety switch starter relayEveryone knows how to identify : cranks, no startclicks, no startno click, no start