Motorola BT100 - Manual (Page 18)

Overview 2-7
BT100 Installation and Operation Manual
Port Locations
Seven port plugs in the cover enable access to internal test points. The input and four output
ports provide connection for coaxial cables and are protected by factory-inserted threaded plugs
or plastic cap plugs. Discard the plastic cap plugs when you install the cable connectors. Port 2
is used only for connection to an external 60 VAC or 90 VAC power supply. Side-by-side
connector fittings are limited to 0.750 inches at ports 1, 2, 3, and 4.
Figure 2-7 illustrates the port locations and the rear view of the housing.
Figure 2-7
Housing port locations and rear view of housing
Power Supply
The integrated DC power supply of the BT100 is a separate circuit board mounted to the
underside of the electronics chassis and is capable of 60 VAC or 90 VAC powering. The
waveshape of the input voltage can be either squarewave or sinewave. The power supply
incorporates power-factor correction that presents a near perfect power factor to the input line.
This reduces the AC current and improves the efficiency of the DC supply system that delivers
2.5 A at 24 VDC. The AC input to the power supply is between 38 VAC and 90VACrms, in two
ranges, with a line frequency from 50 Hz through 60 Hz. A precision output regulator protects
against overcurrent and short circuits. If a short circuit is detected, the power supply shuts
down and the regulator initiates a sequence of line test pulses at approximately one-half second
intervals. The regulator continues these pulses for the duration of the short circuit but returns
to normal operation when the fault is cleared.
The power supply contains a two position 60/90 V selector that sets the start-up voltage for
38 VAC or 55 VAC. The BT100 is shipped with the selector in the 60 V position which is the
standard configuration. The selector should be switched to the 90 V position only for a 90 VAC
system. This sets the start-up voltage at 55 VAC. Because this is only 5 V below 60 VAC, it is