Machine Won't Power On - 8L

Background

The idea of providing power to your machine seems simple: just plug it in. In reality, there are a number of other components used in order to provide power appropriately safety for you and the machine, including (but not limited to):

• The main disconnect switch

• Fuses and/or circuit breakers

• Emergency stop switch/button

• Separate latching circuits for the spindle and rest of the machine

• Transformers, which change the electricity to the appropriate value

Even with all of these components, you can systematically locate nearly any problem with just a multimeter.

Tools

• Digital Multimeter

Twist out the Emergency Stop button

Reason: The Emergency Stop button is pushed in.

1. Twist out the Emergency Stop button and press the Reset button.

The Reset button doesn't illuminate until after you:

1. Twist out the Emergency Stop button.

2. Press the Reset button.

Reset the building’s mains breaker

Reason: The shop or building’s mains breaker is turned off.

1. Examine the building’s breaker. If it's not already on, turn it on.

2. Using a digital multimeter, measure to inspect and verify that you have power at the outlet.

Inspect the power entering the machine

Reason: The Main Disconnect switch is in the Off position.

1. Examine the Main Disconnect switch. If it’s not already in the On position, turn it on and try to take your machine out of reset.

2. Measure the indicated wires in the table below.

   1. If you measure the correct Vac, continue.

   2. If you do not any Vac, you either have a loose wire or a faulty Main Disconnect switch.

Reset the CB1 and/or CB2 circuit breaker

Reason: The CB1 and/or CB2 circuit breaker tripped.

1. Measure the wires as indicated in the table below.

2. If required, power off the machine and reset the tripped breaker.

Inspect the DC power supply (PS1)

Reason: The DC power supply PS1 is defective.

1. Use a digital multimeter measure the Vdc at the wires as indicated in the table below.

2. If the digital multimeter reads below 22 Vdc, identify your machine in the second table and using a digital multimeter measure the input Vac.
   If the input Vac is correct, replace the DC power supply.

Inspect the K1 contactor

Reason: The contactor K1 is defective.

1. Press and hold the Reset button on the operator box and observe the K1. Then release the Reset button and observe the K1.

   1. If the bar only stays in when the button is pressed: There is a loose coil wire, short, or the K1 has malfunctioned.

   2. If the bar never gets pulled in: Go back to the previous troubleshooting topics to ensure your machine is receiving power.