CONTREX CXB2040 - Manual (Page 24)

8900 Zachary Lane N., Maple Grove, MN 55369 U.S.A. 21
CHAPTER FOUR: INSTALLATION
4.1 INTRODUCTION:
This chapter provides the necessary information to make all the wiring connections for the amplifiers
to operate properly.
4.2 MOUNTING:
Appendix A contains all the wiring diagrams, assembly drawings, and mechanical information
necessary to install the amplifiers. The amplifier package should be mounted in a clean, dry enclosure,
free of dust, oil, or other contaminants.
NEVER INSTALL THE AMPLIFIER PACKAGE IN ANY LOCATION WHERE
FLAMMABLE OR EXPLOSIVE VAPORS ARE PRESENT.
IMPORTANT: Muffin fan(s) are mounted along one edge of the baseplate to provide cooling. At
least 3 inches must be allowed between the fan side and the side opposite the fans and any other surface.
The clearance to any other side of the amplifier package is not critical, although sufficient space should be
allowed for easy wiring and servicing.
4.3 WIRING:
4.3.1 RFI/EMI and Wiring Technique:
IMPORTANT: All PWM equipment inherently generates radio-frequency interference (RFI), and
wiring acts as antennae to transmit this interference. In addition, motors inherently generate
electromagnetic interference (EMI). Unless the wiring is very short, some sort of shielding on the motor
wires is necessary to meet FCC RFI/EMI guidelines and to protect other equipment from the effects of
RFI/EMI. We recommend that shielded wire be used, or the wires should be run in metallic conduit. The
shield or conduit should be connected to the amplifier baseplate, which in turn must be earth grounded. In
addition, a conductor of the same gauge as the motor wires must be connected from the motor case to the
amplifier baseplate to provide protection from shock hazard. The earth grounding is necessary to meet
National Electrical Code (NEC) requirements as well as suppressing RFI/EMI.
Additional RFI suppression may be obtained by placing inductors in each motor lead near the
amplifier. Consult a CONTREX applications engineer for inductor recommendations. CONTREX
stocks a complete line of inductors for virtually every application.
IMPORTANT: The signal wiring to the resolver and the signal inputs to the amplifier are
susceptible to noise pickup. Excessive noise pickup will cause erratic amplifier operation. We urge that
each signal input be run in a twisted-pair, shielded cable. The hall-sensor signal lines, the resolver
excitation lines, and the resolver output lines should be run in a three twisted-pair, shielded cable. In each
case the shield should be terminated at the amplifier end only to a common terminal. We also recommend
that the signal lines be kept as far as possible from any power or motor wires.
CHAPTER 4: INSTALLATION