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
- 
  Multimeter 
 
  
  
 Twist Out the Emergency Stop Button
Reason: The Emergency Stop button is pushed in.
- 
  Twist out the Emergency Stop button and press the Reset button. 
The Reset button doesn't illuminate until after you:
- 
    Twist out the Emergency Stop button. 
- 
    Press the Reset button. 
 
  
  
 Reset the Building’s Mains Breaker
Reason: The shop or building’s mains breaker is turned off.
- 
  Examine the building’s breaker. If it’s not already on, turn it on. 
- 
  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.
- 
  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. 
- 
  Measure the voltage coming out of your Main Disconnect switch. 
- 
  Identify the wires as indicated in the table. - 
    If you measure the correct Vac, continue. 
- 
    If you do not any Vac, you either have a loose wire or a faulty Main Disconnect switch. 
 
- 
    
| Machine | Wires | Measure for… | 
|---|---|---|
| PCNC 770 | 91 and 100 | 120 Vac nominal | 
 
  
  
 Check the FU1, FU3 and FU6 Fuses
Reason: Fuse is blown.
- 
  Identify your machines main fuses. 
 
  - 
  Power down the machine, and remove both fuses. 
- 
  Check both fuses using the following process: Checking a Fuse on a Tormach Machine 
- 
  If any fuse is blown, replace it. 
