AMETEK MX15 Series - Manual (Page 39)

User Manual – Rev M California Instruments
MX15 39
The input power cables and protective circuit breaker used must be large enough to handle the
input current and input voltage of the power source and must conform to local electrical codes.
Consult a qualified electrician prior to installation. Table 3-1 shows the size of the cables that
may be used per MX15 cabinet. Note that wires must be sized to accommodate the worst-case
maximum current that may occur under low line conditions. Local electrical codes may also
require different wire types and sizes. These ratings should also be used when selecting a circuit
breaker or equivalent disconnect device.
Cable lengths must not exceed twenty-five (25) feet. For lengths greater than 25 feet, calculate
the voltage drop from the following formula:
2 X DISTANCE X CABLE RESISTANCE PER FT. X CURRENT = VOLT DROP
Table 3-1: Suggested Input Wiring Sizes for each MX Cabinet *
Nominal Line
Voltage
Load Current
@ low line
Wire Gauge (US) Circular Mils
(Kcmils)
Metric (mm2)
480 V 25 Arms 8 AWG 11.50 5.8
400 V 30 Arms 8AWG 11.50 5.8
230 V 52 Arms 8 AWG 18.00 9.1
208 V 58 Arms 6 AWG 26.24 13.3
* Using high temperature rated wire. Always consult the National Electrical Code and/or local code
regulations for proper rating and size of wire cabling prior to installation.
CAUTION: Capacitors in the power source may hold a hazardous electrical charge
even if the power source has been disconnected from the mains supply. Allow
capacitors to discharge to a safe voltage before touching exposed pins of mains
supply connectors.
Power modules need at least 15 Minutes to discharge to safe levels before they can be
removed.
3.5 AC On/Off Circuit Breaker on MX Series front panel.
It is important to understand the purpose and operation of the On/Off circuit breaker of the MX15
located on the left side of the front panel. This is a 2A rated breaker that is used to engage and
protect the LV Power supply of the MX15 chassis only. The LV Power supply provides DC bias
power to the entire MX15 system. The AC input power is routed through a set of three AC line
fuses (F1, F2 and F3) located in the lower right bottom corner of the MX15. (See Figure 3-2 for
fuse locations). These fuses protect the MX amplifier and the AC input transformer from
excessive input currents. The AC input power is connected to the input transformer through a
large three-pole contactor. Removing AC power to the LV Power Supply by opening the front
panel circuit breaker (moving the lever to the down (OFF) position) will cause this contactor to
loose its coil voltage and will result in it opening and disconnecting the input transformer and
amplifier from AC mains input.
Note: If any MX15 system failure has occurred on any part of the MX15 system, AC input
power must be removed immediately and not restored until the system has been
inspected by a qualifier service technician.
Always turn off the On/Off Circuit breaker before re-applying AC input power.