AMETEK MX CTSH - Manual (Page 40)

California Instruments Revision H 40
User Manual MX Series CTSH Compliance Test System
3.5 PACS-3-75 Unit
The PACS-3-75 measurement module can be operated on either 115V or 230 V. It requires less than 0.5
Amps to function.
Note: Check the correct Line input voltage setting of the PACS-3-75 prior to applying line voltage. If
incorrect, move the voltage selection to the correct position before applying power. See paragraph
3.5.4.
3.5.1 Mechanical Installation
The PACS-3-75 is generally installed in the OMNI-3-75 cabinet from the factory. The units are fan cooled,
drawing air in from the sides and exhausting at the rear. The sides of the unit must be kept clear of
obstruction and a 6 inch (152 mm) clearance must be maintained to the rear for proper cooling.
3.5.2 EUT Connection Wiring
See Figure 3-7 through Figure 3-11 for the various MXCTS configuration wiring diagrams. The wire size
used is dictated by the measured currents and voltages. Any wire used must be rated for the maximum
expected current and voltage. The PACS-3-75 unit is rated for 75A RMS maximum per phase when the
rear power terminals are used and therefore AWG 6 is recommended. The wire gauge for the wiring
between the MX30 or MX45 and OMNI-3-75 input should be AWG 4 and is supplied with the MXCTS
system. For MX60 or MX90 CTS systems, sets of AWG4 wires of equal length must be run from both
cabinets and tied together at the OMNI-3-75 AC input terminal block.
The PACS-3-75 is rated for 75 A max. and as such requires the use of at least AWG 6 wire gauge or larger
diameter to connect to the EUT.
Caution: It is important to keep the distance between the PACS-3-75 output and the EUT as
short as possible to avoid adding additional wiring impedance to the test setup.
This is particularly important for flicker test measurements, as the wire impedance will affect the level of any
voltage fluctuations caused by the EUT. Try to limit any output wiring to no more than 5 feet (1.5 meters) or
use larger diameter wire as the distance to the EUT increases. Refer to Figure 3-10.
Caution: Be sure to replace the small rear top cover on the PACS-3-75 unit after the wiring has
been installed, otherwise insufficient cooling of internal components may result. Refer to Figure
3-11 .