2.3 Screen
The full graphics Liquid Crystal Display (LCD) screen is how the PowerMaster
®
communicates
with the user. In computer technology, the screen is the “graphical user interface (GUI).” The
screen displays messages, menus, selection lists, and graphic illustrations.
The display is 5.7” in diameter. It is a full-color VGA (video graphics array) with a resolution of
640 x 480 pixels. A thin piece of clear polycarbonate material is used to protect the screen and is
mounted on top of the display.
2.4 Connector Panel
DIRECT CURRENT
The direct current connector provides direct access to the current inputs of the measuring
standard. The standard current lead set has 3 pairs of banana cables with three test switch
probes (“duckbill”) for phases A, B, C. These probes are meant to insert into the test switch of a
CT rated installation. The three AC current inputs are rated at 20 amps each.
The jack screws used to secure the banana cables to the front panel assembly MUST be
screwed down at all times during testing. This process prevents the possibility of arc
flash from an open secondary in situations where the current leads become free of the
front panel while still inserted into the test switch.
DIRECT VOLTAGE
This connector provides direct access to the voltage inputs of the measuring standard. The
standard voltage lead set has a 6.5 ft. lead terminated with four banana jacks and alligator clips
for phases A, B, C, N. The phase voltage inputs are intended to connect to the potentials of the
metering installation. The four voltage measurement inputs are rated at 600Vac Line to Line, and
350Vac Line to Neutral.
PROBES SET #1 & SET #2
These connectors are used for all other probes (not including the test switch probes). The input
connects to a 3-phase clamp-on probe cable that is terminated with three connectors. One each
for phases A, B and C. They are color-coded red, yellow and blue respectively. When probes
are connected on the end of the 3-phase clamp-on probe cable, the PowerMaster
®
recognizes
the type of probe and calibration detail. To use clamp-on current probes for secondary current
measurements connect them to Set 1. Secondary current probes are normally the MN375
probes. If the secondary probes are connected to Set 1, probes used for CT and PT
WARNING
Rev 1.5
23
