
5.0 SYSTEM DIAGNOSTICS
5-28
CyberCat 254/1016 Operation Manual
UL S2203
Rev 6, 09/2015
P/N: 06-326-2
FM
5.9
VOLTAGES
The main control board has two primary test points that are used when making voltage measurements on the
board:
TP1 = COM
This test point should be used when making DC voltage measurements on the control board.
Connect the voltmeter ground lead to this terminal; then touch the positive lead to the point under
test.
TP2 = 24V
This test point is the + side for the main controller 24VDC power bus (connect the voltmeter
ground to TP1). Check this point if AC power is applied, but the system does not seem to
operate properly.
Exhibit 5-38: Control Board Test Points
LOOP VOLTAGE
Nominally 24 VDC, with a data communication pulse that drops down to a level between 0 - 5
VDC. During normal operation, a meter should measure anywhere from 0 - 24 VDC. It should
never measure a constant 0 VDC.
GROUND FAULT, TP1 to Chassis
With a normal panel and no ground fault, this voltage is 2.17 VDC nominal (<) or 5.0 VDC
nominal (>). If a ground fault is present, this voltage will sway in either direction. Use the
Diagnostic screen to troubleshoot the ground fault. Ground fault detection impedances are 60K
ohm between power ground and chassis ground or 1M ohm between main power and chassis
ground.
Summary of Contents for CyberCat 1016
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