Metering Specification - 565 With Mtm - GE Multilin 565 Instruction Manual

Metering Specification - 565/575 with MTM
The Metering Transducer Module is an optional unit which
can be connected to the 565/575 unit to give additional
functionality. The MTM is used to obtain data for specific
functions which are displayed in the 565/575 or used for
further processing. ** 565 requires Option Card **
Metering Functions
The following data is supplied by the MTM to the 565/575:
• Power Factor
• Frequency
• Kilowatts (kW)
• Kilovars (kVAR)
• Megawatthours (MWhr)
Various alarms and trip levels are set in the 565 for the above
parameters as required.
The following levels are derived from MTM data and calcu-
lated in the 565/575. They are:
• Kilowatt Demand
• Kilovars Demand
MTM Communications
The 565/575 communicates with the MTM via a dedicated
port and uses a proprietary protocol.
Port Information
The dedicated port uses the RS485 type arrangement and
requires a shielded twisted pair cable. The MTM is used as a
slave and responds only after a request by the 565/575. A
request is sent every 500 ms. The MTM responds with data
which must occur within a set period of time.
A checksum of the data packet is used to verify data trans-
missions. If an error has occurred or the MTM will not
respond, the 565/575 will resend the request. In the event
that the 565/575 has requested data three times and no
response has been received an MTM communications alarm
will occur, if enabled.
Revision Number
A revision Number is used in the transmission protocol
between the MTM and the 565/575 to identify the software
level in the 565/575 and the MTM. If the revisions are not
compatible then an MTM communications alarm is declared.
Function Enhancement with MTM
The following functions with their specifications become
available when an MTM and Option Card has been added to
the 565/575.
FEATURE INFORMATION
Power Factor
Ratio of real power (kW) to apparent power (kVAR). The
range is from 0 leading (+ve values) to 1 to 0 lagging (-ve
values) to 1.
Setpoints:
Alarm level 0 leading to 1 and 0 lagging to 1, in steps of
0.05. Default values 0.75 leading and lagging.
Alarm delay 1-127 sec, in steps of 0.5 sec. Default 5
seconds.
Alarm relay AUX 1, 2 and AUX 1&2. Default AUX 1.
Trip level 0 leading to 1 and 0 lagging to 1, in steps of
0.05. Default values 0.7 leading and lagging.
Trip delay 1-127 sec, in steps of 0.5 sec. Default 1
second.
Trip relay TRIP , AUX 1, 2, TRIP & AUX1, TRIP & AUX2,
AUX 1&2, and TRIP & AUX 1&2. Default AUX
1.
Frequency
Line frequency measured between the phases A and B
voltages.
The range is 40-72 Hz. This allows for measurements of up to
± 20% of 50 or 60 Hz. The resolution is 0.1 Hz.
Setpoints:
Alarm level 40-60Hz for Underfrequency and 50-72Hz for
Overfrequency, in steps of 0.1 Hz. Default
value 58 and 62 for Under/Over freq.
Alarm delay 1-127 sec, in steps of 0.5 sec. Default value 5
seconds.
Alarm relay AUX 1, 2, and AUX 1&2. Default AUX 1.
Trip level 40-60Hz for Underfrequency and 50-72Hz for
Overfrequency, in steps of 0.1 Hz. Default
value 56 and 64 for Under/Over freq.
Trip delay 1-127 sec, in steps of 0.5 sec. Default value 1
second.
Trip relay TRIP , AUX 1, 2, TRIP & AUX1, TRIP & AUX2,
AUX 1&2, and TRIP & AUX 1&2. Default AUX
1.
kW
This measures real power and is supplied by the MTM for
metering purposes only. There are no alarm or trip functions.
Range is up to 65 000 kW (65 MW).
Accuracy is ±2% of displayed.
Resolution display is 1 kW.
kVAR
This is a measure of reactive power. This value is supplied by
the MTM and is for metering purposes only. There are no
alarm or trip functions.
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