Tormach PCNC 770 - Details of Power Distribution Subsystem

Chapter 10
184
UM10350_PCNC770_Manual_0916A
Troubleshooting
10.5.1.2 Details of Power Distribution Subsystem
The PCNC mill is powered by an operator provided nominal 120/1/60 (120 V single phase, 60 HZ) 20
amp, 3-wire electrical circuit in North America. If only 220 VAC is available, a step down transformer
is required. Operaonal PCNC mill voltage range is from 115 VAC to 135 VAC.
NOTE: The system funcons down to 100 VAC, but operang below 115 VAC diminishes torque at high
spindle speeds.
The two current carrying conductors of this supply are connected to the Main Disconnect, located
on the right side of the electrical cabinet. When the Main Disconnect is in the o posion, no
power is supplied to the mill. Find the relevant poron of the electrical schemac highlighted in
Figure 10.5. For more detail, view electrical schemac inside back cover.
One leg of the two current carrying conductors is grounded. A third wire ground must also be
provided. The ungrounded leg of this supply is connected to a third pole on the Main Disconnect
described above. Running the circuit in this manner allows the coolant pump outlet to be controlled
either automacally by the mill controller or manually depending on the posion of the coolant
switch, SW5, on the Operator Panel (see Figure 10.7). The circuit also provides power to two outlets
which can be used for the controller and monitor. These outlets are controlled by SW6, labeled
Controller, on the Operator Panel. This allows turning o of the controller when mill power is sll
on. Turning the Main Disconnect to the o posion powers o the coolant and controller outlets.
Figure 10.7
Start
E-stop
Machine
LED
Coolant
Controller
Operator Panel