PQ – Power Quality, Sags and Swells
Method
The Model 928A measures sags, swells and power in-
terruptions by using the
PQ
power quality triggering
function.
PQ
follows the CBEMA method of mea-
suring the signals at Channels A and B, comparing
them to point limits over assigned time intervals. The
rules used to measure the two input signals, including
Point Limits, are called a Profile. An example of the
CBEMA method used in the 928A is illustrated below.
Figure 4, drawn in a manner after the CBEMA
method, models some sag/swell voltage limits and time
intervals set in the 928A. Time intervals are normally
configured as an integer multiple of a half cycle at the
nominal frequency.
Figure 4:
Point Limit Profile
48
Summary of Contents for 928A
Page 1: ...MODEL 928A USER S MANUAL Arbiter Systems Inc Paso Robles CA 93446 U S A ...
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Page 57: ...Channel B Combined Caution For current probe use see CT Probe Use on page 4 43 ...
Page 112: ...CT Cable Connector Figure 16 CT Cable Connector side view Figure 17 CT Connector End View 98 ...
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Page 115: ...CE Mark Certification ...