American Magnetics 420 Power Supply Programmer - Manual (Page 33)

Rev. 7 15
Installation
Power Requirements
2.4 Collecting Necessary Information
In order to properly configure the Model 420, certain system information is
required. Such parameters as the magnet physical properties, type of
power supply, persistent switch heating current requirements, and voltage
and current constraints of the magnet are entered into the instrument
once and the battery-backed memory will retain the data even after power
is removed from the instrument. An example of the data to be entered and
how it is entered is described in paragraph 3.2.5 on page 50.
If the Model 420 was purchased as part of a magnet system, essential data
has already been entered at the AMI factory and a configuration sheet
should be provided detailing the settings.
2.5 System Interconnects
The following diagrams will assist the user in system equipment setup. If
the Model 420 was purchased as part of a magnet system, all applicable
system components and wiring harnesses will be shipped with the system.
Since many different configurations are possible, use the system
interconnection diagram that most closely corresponds with your system;
this is usually denoted by the operating characteristics of the power
supply.
For maximum immunity to AC line noise, ensure that the chassis of the
Model 420 has a direct, low impedance electrical connection to the chassis
of the power supply to which the
352*5$0 287 is connected. The
connection can be made via a grounding strap, or if rack mounted, through
the rack itself if it is constructed of electrically-conductive material.
Caution
The wiring between the power supply and the vapor-cooled current
leads must be of sufficient size to carry the full rated current of the
power supply. Typically, for short runs (less than 25 ft (7.6 m)) for
100 amperes 4 AWG wire is sufficient and for 200 amperes, 2 AWG
is sufficient.
Note that an AMI Model 13x Liquid Helium Level Instrument is shown as
a possible component of each system. The main instrumentation cable
connecting the magnet support stand and the Model 420 Magnet Station
Connector J7A and J7B contains all the instrumentation and control
connections needed to control and monitor the magnet. The signals in this
cable which are required to monitor LHe level and temperatures are also
presented at the LHe Level / Temp connectors J8A and J8B. Refer to the
Appendix for pin-outs of these and other connectors.