GE PQM II Power QualIty Meter

easy local interface. Standard models have

RS485 communications for programming

and monitoring. Users can replace

expensive additional devices by-adding

the CONTROL, TRANS DUCER and POWER

analysis options to the PQM II as required.

alarms

Any of the assignable outputs may be

used to trigger an alarm for specific

applications. Simple alarm messages

provide easy notification

ConDItIon

aPPlICatIon

motors/transformers

pumps/compressors

leakage/unbalance

motors

overcurrent

undercurrent

neutral current

current unbalance

overvoltage

undervoltage

phase sequence

overfrequency

underfrequency

power factor

switch input

equipment protection

motors/load transfer

pumps/equipment

generators

load shedding

capacitor banks

process control

Communications

Integrate process, instrumentation

and electrical requirements in a plant

automation system by connecting PQM II

meters to a DCS or SCADA system. Initially

PQM II meters can be used as stand-alone

units. Open architecture allows connection

to other ModBus® compatible devices

on the same communication link. At a

later stage PQM II can be integrated in a

complete plant wide system for overall

process monitoring and control.

The standard PQM II comes complete

with a rear RS485 and front RS232 port.

RS232 port can be used for data collection,

printing reports or problem analysis without

disturbing the main RS485 communication

interface at rear. The standard meter

provides:

•    RS485    ModBus®    1.200    to    19.200‑bps

•    DNP    3.0    Level    2    Protocol

•    Mini    RTU    SCADA    system    component

•    Measure    actual    values

•    Read    status

•    Issue    control    commands

•    Load    all    setpoints    from    a    file

•    Change    individual    setpoints

A computer running EnerVistaTM software

can change system setpoints, monitor

values, status and alarms. Continuous

monitoring minimizes process downtime

by immediately identifying potential

problems due to faults or changes.

Future expansion

The PQM II uses non-volatile flash memory

for firmware storage. This allows future

product upgrades to be loaded via

the serial port. Upgrades can also be

downloaded from the GE Multilin website.

options

There are a variety of options available

to the user, allowing a range of custom

configurations:

transducer

Four analog outputs: Four isolated analog

outputs can be used to replace eight

analog transducers. Output signals can

be selected from any of the measured

parameters for direct interface to a PLC or

other devices.

analog Input: PQM II meter can accept

two analog inputs from external devices.

Meter can be programmed to activate a

control relay based on analog input from

transducers (temperature, level etc.)

Communications

second rear Comm Port: An additional

rear RS485 comm port is provided for

simultaneous monitoring by process,

instrument, electrical or maintenance

personnel.

Control

Three output relays and four inputs allow

measured parameters from the standard

PQM II to be combined with setpoints

and I/Os for control applications. With the

control option, three output relays and

four switch inputs are added along with

programmable set points to make

a mini RTU. Output relays can also be

controlled via the communication port or

assigned to different setpoints for custom

programming to accommodate many

applications such as:

•    Undercurrent    alarm    for    pumps

•    Over    and    undervoltage    for    generators

•    Unbalance    alarm    for    rotating    machines

•    Dual    level    power    factor    for    capacitor

bank switching

•    Underfrequency/demand    output    for

load shedding resulting in power cost

savings

•    kWh,    kvarh    and    kVAh    pulse    output    for

PLC interface

Power analysis

Data Logger (Trending): Trending is

useful as a trouble shooting aid when a

problem is detected. Measured values

can be selected and plotted with a

programmable sampling rate to suit the

time interval of interest. The generated

chart recorder screen can be printed or

exported to other programs for report

writing.

Harmonic analysis: Non linear loads such

as variable speed drives, computers and

electronic ballasts can cause harmonics

which may lead to problems such as

nuisance breaker tripping, telephone

interference, transformer, capacitor or

motor overheating. Harmonic analysis