What is the first thing a technician should do before performing diagnosis on any electrical circuit?
Perform starter circuit voltage drop tests; determine needed repairs. Disable the ignition and fuel system before performing these tests. Check the voltage drop between each component in the starter circuit while operating the starter motor. Voltage drop between each component should not exceed .
Which circuit protection device is normally found in the engine compartment near the battery?
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When load testing a battery the load applied to the battery should be?
The Load Test requires a high rate discharge tester to be connected to the battery. The load should be set to 1/2 the Cold Cranking Amps (CCA) or 3 times the Amp-Hour rating. The load should be applied for 15 seconds and the voltage should not drop below 9.6V (at a battery temperature of 70°F or 21°C).
Which of the following effects does unwanted resistance have on a circuit?
You need the resistance of the load of an electric circuit in order for the circuit to function, but if you have unwanted resistance, the circuit will not function as intended.
How do you carry out a voltage drop test?
To check the entire circuit, connect the meter positive lead to a clean spot on the starter motor case and the meter negative lead to the negative battery post. Crank the engine and note the reading. The voltage drop on the negative side should be 0.3 volts or less.
What are the acceptable cable voltage drop readings for a 12 volt charging system?
Your drop voltage should be between 0.3 volts and 0.5 volts:
- If your reading is below 0.3 volts, have the alternator checked to make sure it is charging. Consult your repair manual for this specifications, if necessary.
- If your reading is over 0.5 volts, check each connection in the power side of the circuit.
What would cause a voltage drop?
Causes of Voltage Drop Excessive dropping is due to increased resistance in a circuit, typically caused by an increased load, or energy used to power electric lights, in the form of extra connections, components, or high-resistance conductors.
How do you fix voltage drop?
The simplest way to reduce voltage drop is to increase the diameter of the conductor between the source and the load, which lowers the overall resistance. In power distribution systems, a given amount of power can be transmitted with less voltage drop if a higher voltage is used.
How much voltage drop does it take to cause problems to a motor?
In general, satisfactory motor performance requires a voltage within ± 5% of its rated nominal value in steady-state operation, Starting current of a motor can be 5 to 7 times its full-load value (or even higher). If an 8% voltage drop occurs at full-load current, then a drop of 40% or more will occur during start-up.
Will low voltage damage a motor?
Just as higher voltages can help reduce motor operating temperatures, low voltage is a major cause of motor overheating and premature failure. A low voltage forces a motor to draw extra current to deliver the power expected of it thus overheating the motor windings.
What happens if you increase the current in a motor?
An increase in current is a danger to the motor only if that current exceeds the motor’s nameplate current rating. When amps go above the nameplate rating, heat begins to build up in the motor. Without a timely correction, this heat will damage the motor.
Why does motor current increase with load?
In an electric motor, almost all types, the current is proportional to the torque. If the load increases, in other words, the torque increases and the current will increase. The magnetic field in a motor are related to the voltages. The rotor produces a field that turns at the same speed as the supply.
What happens if the amps are too high?
A higher voltage than a device is designed for will most likely blow up some components, but amperage is derived from how much current is actually drawn, based on the device’s resistance, so having “too much” is not a problem and will do no harm.
Why do amps go up when voltage goes down?
Amps go up when you increase voltage. UNLESS you change out the load (motor) to compensate for the higher voltage. High voltage setups make power with lower amperage because they use motors with a much lower kv. Yes these are correct.
What happens to amps when voltage increases?
Ohm’s law states that the electrical current (I) flowing in an circuit is proportional to the voltage (V) and inversely proportional to the resistance (R). Therefore, if the voltage is increased, the current will increase provided the resistance of the circuit does not change.
Is lower or higher amps better?
Higher voltage is better when current has to travel long distances. A low amp and high voltage system allows you to reduce the amount of electrical current, so less of it is lost as it travels through wires, while still delivering the same amount of horsepower at the end.
Do amps increase with voltage?
Generally, what it means to increase voltage for real will also result in an increase of amps. So, when voltage increases from a power source, amperes also increase. Your power source sets up the wattage, [I × E] Watts . So, when your power increases in fact, amps necessarily would follow suit.
Does a higher Ah battery give more power?
The Ah, or ‘Amp hours’ rating of the battery, indicates the amount of charge that is stored in the battery. Basically, the higher the number, the more energy that is stored. Ah ratings affect the run time and performance of the tool.
Does higher voltage mean longer battery life?
A higher voltage battery has the potential to “push” more current–that is, more electrons–for a given resistance. This translates to the capacity for greater work, which is the same thing as more power. Higher voltage also means less current to do the same amount of work, so longer battery life.
Does higher resistance drain a battery faster?
The power consumed by your circuit determines how fast the battery drains. Since the voltage doesn’t change, when the resistance goes up, the current and the power go down. So, adding series resistance to the circuit will make your battery last longer.
Does a battery lose voltage over time?
The voltage will go down with use, but in many applications the increased internal resistance will render the battery unusable long before the reduced voltage does. So yes the voltage drops as the batteries get used up, and also the internal resistance rises.
How long does a 4.0 Ah battery last?
2 hours
Whats the difference between a 2.0 Ah battery and a 4.0 Ah battery?
What is the difference between the 2ah and 4ah batteries? It would be equivalent to having a larger gas tank, you would get a longer run time before having to refill it, or in the case of the battery, recharge it. The 4Ah would give you approximately twice the run time as the 2Ah.
Can I use a 5Ah battery instead of 4Ah?
Yes, it can be used and how the exchange would look like. If you are using a 4Ah battery and heading towards the 5Ah would mean that your application could run up to 25% longer. In contrast, if you want to change from 5Ah to 4Ah, this means your electric device will run up to 20-23%.
Can I use a 5Ah battery instead of 2Ah?
All that to say, you can pretty much make a straight comparison that any brand’s 18V (or 20V max) 5Ah battery will hold more than double the charge of any other 18V (or 20V max) 2Ah battery.