Voltage change detail
72
CHAPTER 6:
Service
Model 648 Electromagnet Power Supply
6.6 Circuit Breaker
Setting
The main three-phase input power is protected by an automatic-reset circuit breaker
within the instrument. A smaller, start-up power supply is fused separately and
discussed in section 6.7. If the breaker trips, it will reset within a few minutes and the
unit can be restarted. If the unit trips again after a short time, the circuit breaker trip
current may be set incorrectly. TABLE 6-1 shows required voltage and current
settings.
Voltage and current selection
Voltage tap
Circuit breaker
200 V
50 A
208 V
50 A
220 V
46 A
230 V
46 A
380 V
37 A
400 V
37 A
415 V
37 A
To avoid potentially lethal shocks, turn off the power supply and disconnect it from AC
power before performing this procedure. For continued protection against fire hazard,
use only the recommended current setting for the line voltage selected.
Use this procedure to verify or change the circuit breaker current setting.
1. Turn the front panel line power switch off.
2. Remove the main power from the Model 648 using the disconnect switch.
3. Identify the power wiring access panel on the rear of the Model 648.
4. Remove the perimeter screws holding the power wiring access panel.
5. Refer to FIGURE 6-2 to locate the fuse detailed in FIGURE 6-5.
FIGURE 6-3
TABLE 6-1
