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10.1 GENERAL
HIGH VOLTAGES ARE PRESENT ON THE REAR TERMINALS OF THE RELAY, CAPABLE OF
CAUSING DEATH OR SERIOUS INJURY. USE CAUTION AND FOLLOW ALL SAFETY RULES
WHEN HANDLING, TESTING, OR ADJUSTING THE EQUIPMENT.
CAUTION
DO NOT OPEN THE SECONDARY CIRCUIT OF A LIVE CT, SINCE THE HIGH VOLTAGE PRO-
DUCED IS CAPABLE OF CAUSING DEATH OR SERIOUS INJURY, OR DAMAGE TO THE CT
INSULATION.
CAUTION
THE RELAY USES COMPONENTS WHICH ARE SENSITIVE TO ELECTROSTATIC DIS-
CHARGES. WHEN HANDLING THE UNIT, CARE SHOULD BE TAKEN TO AVOID ELECTRICAL
DISCHARGES TO THE TERMINALS AT THE REAR OF THE RELAY.
CAUTION
ENSURE THAT THE CONTROL POWER APPLIED TO THE RELAY, AND THE AC CURRENT
AND VOLTAGE INPUTS, MATCH THE RATINGS SPECIFIED ON THE RELAY NAMEPLATE. DO
NOT APPLY CURRENT TO THE CT INPUTS IN EXCESS OF THE SPECIFIED RATINGS.
CAUTION
ENSURE THAT THE LOGIC INPUT WET CONTACTS ARE CONNECTED TO VOLTAGES BELOW
THE MAXIMUM VOLTAGE SPECIFICATION OF 300 V DC.
CAUTION
The following conventions are used for the remainder of this chapter:
•
All setpoints and actual values are mentioned with their path as a means of specifying where to find the
particular message. For instance, the setpoint WINDING 1 PHASE CT PRIMARY, which in the message struc-
ture is located under setpoints page S2, would be written as:
SETPOINTS/S2 SYSTEM SETUP/WINDING 1/WINDING 1 PHASE CT PRIMARY
•
Normal phase rotation of a three-phase power system is ABC.
•
The phase angle between a voltage signal and a current signal is positive when the voltage leads the cur-
rent.
•
Phase A to neutral voltage is indicated by V
•
Phase A to B voltage is indicated by V
•
The neutral current signal is the 3 I
•
The ground current is the current signal measured by means of a CT in the power transformer connection
to ground.
10
10-2
(arrowhead on the "a").
an
(arrowhead on the "a").
ab
signal derived from the three phase currents for any given winding.
o
745 Transformer Management Relay
10 COMMISSIONING
10.1.3 SAFETY PRECAUTIONS
10.1.4 CONVENTIONS
GE Power Management
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