GE Pqm 2 Manual

							CHAPTER 2: INSTALLATION
PQMII POWER QUALITY METER  – INSTRUCTION MANUAL2–11
For a single-phase connection, connect current and voltage to the phase A inputs only. All 
other inputs are ignored. Select the 
S2 SYSTEM SETUP  CURRENT/VOLTAGE CONFIGURATION  VT 
WIRING:
 “SINGLE PHASE” setpoint .
FIGURE 2–8: Single Phase Connection 
						

							2–12PQMII POWER QUALITY METER  – INSTRUCTION MANUAL
CHAPTER 2: INSTALLATION
2.2.3 3-wire System using Two CTs
The f igure below shows two methods for connecting CTs to the PQMII for a 3-wire system. 
The top drawing shows the standard wiring conf iguration using three CTs. An alternate 
wiring conf iguration uses only two CTs. With the two CT method, the third phase is 
measured by connecting the commons from phase A and C to the phase B input on the 
PQMII. This causes the phase A and phase C current to flow through the PQMII’s phase B CT 
in the opposite direction, producing a current equal to the actual phase B current .
Ia + Ib + Ic = 0 for a three wire system.
Ib = – (Ia + Ic)
For the CT connections above, the 
S2 SYSTEM SETUP  CURRENT/VOLTAGE CONFIGURATION  
PHASE CT WIRING  PHASE CT PRIMARY
 setpoint must be set to PHASE A, B, AND C. 
FIGURE 2–9: Alternate CT Connections for 3-wire System 
						

							CHAPTER 2: INSTALLATION
PQMII POWER QUALITY METER  – INSTRUCTION MANUAL2–13
2.2.4 Control Power
The control power supplied to the PQMII must match the installed power supply. If the 
applied voltage does not match, damage to the unit may occur. Check the product 
identif ication to verify the control voltage matches the intended application.
A universal AC/DC power supply is standard on the PQMII. It covers the range 90 to 300 V 
DC and 70 to 265 V AC at 50/60 Hz. It is not necessary to adjust the PQMII if the control 
voltage is within this range. A low voltage power supply is available as an option. It covers 
the range 20 to 60 V DC and 24 to 48 V AC at 50/60 Hz. Verify from the product 
identif ication label that the control voltage matches the intended application. Connect the 
control voltage input to a stable source for reliable operation. A 2.5 A HRC fuse is 
accessible from the back of the PQMII via the fuse access door. Consult the factory for 
replacement fuses, if required. Using #12 gauge wire or ground braid, connect Terminals 5 
and 6 to a solid system ground, typically a copper bus in the switchgear. The PQMII 
incorporates extensive f iltering and transient protection to ensure reliable operation under 
harsh industrial operating environments. Transient energy must be conducted back to the 
source through Filter Ground Terminal (5). The Filter Ground Terminal (5) is separated from 
the Safety Ground Terminal (6) to allow dielectric testing of switchgear with the PQMII 
wired up. Filter Ground Terminal connections must be removed during dielectric testing.
When properly installed, the PQMII meets the interference immunity requirements of IEC 
801 and ANSI C37.90.1.
2.2.5 VT Inputs
The PQMII accepts input voltages from 0 to 600 V AC between the voltage inputs (V1, V2, 
V3) and voltage common (Vn). These inputs can be directly connected or supplied through 
external VTs. If voltages greater than 600 V AC are to be measured, external VTs are 
required. When measuring line-to-line quantities using inputs V1, V2, and V3, ensure that 
the voltage common input Vn is grounded. This input is used as a reference for measuring 
the voltage inputs.
All connections to the PQMII voltage inputs should be connected using HRC fuses rated at 
2 Amps to ensure adequate interrupting capacity.
2.2.6 CT Inputs
Current transformer secondaries of 1 A or 5 A can be used with the PQMII for phase and 
neutral sensing. Each current input has 3 terminals: 5 A input , 1 A input , and common. 
Select either the 1 A or 5 A terminal and common to match the phase CT secondary. 
Correct polarity as indicated in the wiring diagrams is essential for correct measurement of 
all power quantities.
The CTs selected should be capable of supplying the required current to the total 
secondary load, including the PQMII burden of 0.1 VA at rated secondary current and the 
connection wiring burden.
All PQMII internal calculations are based on information measured at the CT and VT inputs. 
The accuracy specif ied in this manual assumes no error contribution from the external CTs 
and VTs. To ensure the greatest accuracy, Instrument class CTs and VTs are recommended. 
						

							2–14PQMII POWER QUALITY METER  – INSTRUCTION MANUAL
CHAPTER 2: INSTALLATION
2.2.7 Output Relays
The basic PQMII comes equipped with one output relay; the control option supplies three 
additional output relays. The PQMII output relays have form C contacts (normally open 
(NO), normally closed (NC), and common (COM)). The contact rating for each relay is 5 A 
resistive and 5 A inductive at 250 V AC. Consult 1.6: Specifications for contact ratings under 
other conditions. The wiring diagrams show the state of the relay contacts with no control 
power applied; that is, when the relays are not energized. Relay contact wiring depends on 
how the relay operation is programmed in the 
S3 OUTPUT RELAYS setpoint group (see 5.4: S3 
Output Relays for details).
•Alarm Relay (Terminals 43/44/45): A selected alarm condition activates the alarm 
relay. Alarms can be enabled or disabled for each feature to ensure only desired 
conditions cause an alarm. If an alarm is required when control power is not present , 
indicating that monitoring is not available, select “Fail-safe” operation for the alarm 
relay through the 
S3 OUTPUT RELAYS  ALARM RELAY  ALARM OPERATION setpoint . The NC/
COM contacts are normally open going to a closed state on an alarm. If “Unlatched” 
mode is selected with setpoint 
S3 OUTPUT RELAYS  ALARM RELAY  ALARM ACTIVATION, the 
alarm relay automatically resets when the alarm condition disappears. For “Latched” 
mode, the key must be pressed (or serial port reset command received) to reset the 
alarm relay. Refer to 6.3.1: Alarms for all the displayed alarm messages. 
•Auxiliary Relays 1,2,3 (Optional; Terminals 34 to 42): Additional output relays can be 
conf igured for most of the alarms listed in 6.3.1 Alarms. When an alarm feature is 
assigned to an auxiliary relay, it acts as a control feature. When the setpoint is 
exceeded for a control feature, the output relay changes state and the appropriate 
Aux LED lights but no indication is given on the display. The auxiliary relays can also be 
programmed to function as kWh, kvarh, and kVAh pulse outputs.
2.2.8 Switch Inputs (Optional)
With the control (C) option installed the PQMII has four programmable switch inputs that 
can be used for numerous functions. The f igure below shows the internal circuitry of the 
switches.
FIGURE 2–10: Switch Input Circuit
EXTERNAL
SWITCH
OPTO
ISOLATION
TYPICAL
SWITCH
TERMINALSISOLATED
POWER
SUPPLY
+24VDC
PQM II
TO LOGIC
10mA
PULSED
FILTERIN COM 
						

							CHAPTER 2: INSTALLATION
PQMII POWER QUALITY METER  – INSTRUCTION MANUAL2–15
Each switch input can be programmed with a 20-character user def ined name and can be 
selected to accept a normally open or normally closed switch. A list of various functions 
assignable to switches is shown below, followed by a description of each function.
•Alarm Relay: When a switch input is assigned to the alarm relay, a change in the 
switch status produces an alarm condition and the alarm relay activates.
•Pulse Input 1/2/3/4: When a switch input is assigned as a pulse input counter, the 
PQMII counts the number of transitions from open to closed when the input is 
conf igured as normally open and closed to open when the input is conf igured as 
normally closed. The minimum pulse width required for the PQMII to read the switch is 
150 ms. Therefore, for the PQMII to read one pulse, the switch input must be in its 
inactive state (closed/open) for a minimum of 150 ms then in its active state (open/
closed) for another 150 ms. See 1.6: Specifications for more details.
•New Demand Period: The PQMII can be used for load shedding by assigning a switch 
input to a new demand period. This allows the PQMII demand period to be 
synchronized with the utility meter. One of the billing parameters used by a utility is 
peak demand. By synchronizing the PQMII to the utility meter, the PQMII can monitor 
the demand level read by the utility meter and perform load shedding to prevent the 
demand from reaching the penalty level. The utility meter provides a dry contact 
output which can be connected to one of the PQMII switch inputs. When the PQMII 
senses a contact closure, it starts a new demand period (with Block Interval Demand 
calculation only).
•Setpoint Access: The access terminals must be shorted together in order for the 
faceplate keypad to have the ability to store new setpoints. Typically the access 
terminals are connected to a security keyswitch to allow authorized access only. Serial 
port commands to store new setpoints operate even if the access terminals are not 
shorted. When the access terminals are open, all actual and setpoint values can still 
be accessed for viewing; however, if an attempt is made to store a new setpoint value, 
the message 
SETPOINT ACCESS DISABLED is displayed and the previous setpoint 
remains intact . In this way, all of the programmed setpoints remain secure and 
tamper proof.
•Select Analog Output: This switch selection allows each analog output to be 
multiplexed into two outputs. If the switch is active, the parameter assigned in 
setpoint 
S2 SYSTEM SETUP  ANALOG OUTPUT 1  ANALOG OUTPUT 1 ALT determines the 
output level. If the switch is not active, the parameter assigned in setpoint 
S2 SYSTEM 
SETUP  ANALOG OUTPUT 1  ANALOG OUTPUT 1 MAIN
 is used. See the following section 
and 5.3.2: Analog Outputs for additional details.
•Select Analog Input: This switch selection allows the analog input to be multiplexed 
into two inputs. If the switch is active, the parameter assigned in setpoint 
S2 SYSTEM 
SETUP  ANALOG INPUT  ANALOG INPUT ALT
 is used to scale the input . If the switch is not 
active, the parameter assigned in setpoint 
S2 SYSTEM SETUP  ANALOG INPUT  ANALOG 
INPUT MAIN
 is used. If a relay is assigned in S2 SYSTEM SETUP  ANALOG INPUT  ANALOG IN 
MAIN/ALT SELECT RELAY
, that relay energizes when the switch is active and de-energizes 
when the switch is not active, thus providing the ability to feed in analog inputs from 
two separate sources as shown in the figure below. See the 2.2.10: Analog Input 
(Optional) section below for details. Refer to 5.3.3: Analog Input for additional details. 
						

							2–16PQMII POWER QUALITY METER  – INSTRUCTION MANUAL
CHAPTER 2: INSTALLATION
FIGURE 2–11: Analog Input Multiplexing
•Aux 1/2/3 Relay: When a switch input is assigned to an Auxiliary relay, a closure on 
the switch input causes the programmed auxiliary relay to change state. This 
selection is available only if the Control (C) option is installed.
•Clear Energy: When a switch input is assigned to “Clear Energy”, a closure on the 
switch input will clear all Energy data within the PQMII.
•Clear Demand: When a switch input is assigned to “Clear Demand”, a closure on the 
switch input will clear all Demand data within the PQMII.
2.2.9 Analog Outputs (Optional)
The PQMII has four current outputs when the transducer option is installed (T20 = 4 to 20 
mA, T1 = 0 to 1 mA in the order code). These outputs can be multiplexed to produce 8 
analog transducers. This output is a current source suitable for connection to a remote 
meter, chart recorder, programmable controller, or computer load. Use the 4 to 20 mA 
option with a programmable controller that has a 2 to 40 mA current input . If only a 
voltage input is available, use a scaling resistor at the PLC terminals to scale the current to 
the equivalent voltage. For example, install a 500Ω resistor across the terminals of a 0 to 
10 V input to make the 4 to 20 mA output correspond to 2 to 10 V (R = V/I = 10 V / 0.02 A = 
500Ω). Current levels are not affected by the total lead and load resistance which must not 
exceed 600Ω for the 4 to 20 mA range and 2400Ω for the 0 to 1 mA range. For readings 
greater than full scale the output will saturate at 22 mA (4 to 20 mA) or 1.1 mA (0 to 1 mA). 
These analog outputs are isolated and since all output terminals are floating, the 
connection of the analog output to a process input will not introduce a ground loop. Part of 
the system should be grounded for safety, typically at the programmable controller. For 
floating loads (such as a meter), ground Terminal 24 externally.
The outputs for these transducers can be selected from any of the measured parameters 
in the PQMII. The choice of output is selected in the 
S2 SYSTEM SETUP  ANALOG OUTPUT 1(4) 
setpoints group. See 5.3.2: Analog Outputs for a list of available parameters. Each analog 
output can be assigned two parameters: a main parameter and an alternate parameter. 
Under normal operating conditions, the main parameter will appear at the output 
terminals. To select the alternate parameter, one of the switch inputs must be assigned to 
“SELECT ANALOG OUT” and the switch input must be closed (assuming normally closed 
activation). By opening and closing the switch input , two analog output parameters can be 
multiplexed on one output . This effectively achieves 8 analog outputs for the PQMII. 
						

							CHAPTER 2: INSTALLATION
PQMII POWER QUALITY METER  – INSTRUCTION MANUAL2–17
FIGURE 2–12: Analog Output
As shown in wiring diagrams, these outputs are at Terminals 25 to 28 and share Terminal 
24 as their common. Shielded cable should be used, with only one end of the shield 
grounded, to minimize noise effects.
Signals and power supply circuitry are internally isolated, allowing connection to devices 
(PLCs, computers, etc.) at ground potentials different from the PQMII. Each terminal, 
however, is clamped to ±36 V to ground.
2.2.10 Analog Input (Optional)
Terminals 22(–) and 23(+) are provided for a current signal input . This current signal can be 
used to monitor any external quantity, such as transformer winding temperature, battery 
voltage, station service voltage, transformer tap position, etc. Any transducer output 
ranges within the range of 0 to 20 mA can be connected to the analog input terminals of 
the PQMII. See 5.3.3: Analog Input for details on programming the analog input .
2.2.11 RS485 Serial Ports
A fully loaded PQMII is equipped with three serial ports. COM1 is a RS485 port available at 
the rear terminals of the PQMII which is normally used as the main communications 
interface to the system. COM2, which is also a rear RS485 port , can be used for data 
collection, printing reports, or problem analysis without disturbing the main 
communications interface. COM3 is a front panel RS232 port that can be used for setpoint 
programming or recording using the EnerVista PQMII Setup Software.
A serial port provides communication capabilities between the PQMII and a remote 
computer, PLC, or distributed control system (DCS). Up to thirty-two PQMIIs can be daisy 
chained together with 24 AWG stranded, shielded, twisted-pair wire on a single 
communication channel. Suitable wire should have a characteristic impedance of 120 W 
(such as Belden #9841). These wires should be routed away from high power AC lines and 
other sources of electrical noise. The total length of the communications wiring should not 
exceed 4000 feet for reliable operation. Correct polarity is essential for the 
communications port to operate. Terminal (485+) of every PQMII in a serial communication 
link must be connected together. Similarly, the (485–) terminal of every PQMII must also be 
connected together. These polarities are specif ied for a 0 logic and should match the 
polarity of the master device. If the front panel RX1 or RX2 lights are flashing, this indicates 
that the PQMII is receiving data. If the front panel TX1 or TX2 lights are flashing, this 
823700A1.CDR
PQMII 
						

							2–18PQMII POWER QUALITY METER  – INSTRUCTION MANUAL
CHAPTER 2: INSTALLATION
indicates that the PQMII is transmitting data. Each PQMII must be daisy-chained to the 
next one as shown in the f igure below. Avoid star or stub connected conf igurations. If a 
large difference in ground potentials exists, communication on the serial communication 
link will not be possible. Therefore, it is imperative that the serial master and PQMII are both 
at the same ground potential. This is accomplished by joining the RS485 ground terminal 
(Terminal 46 for COM1; Terminal 49 for COM2) of every unit together and grounding it at the 
master only.
The last PQMII in the chain and the master computer require a terminating resistor and 
terminating capacitor to ensure proper electrical matching of the loads and prevent 
communication errors. Using terminating resistors on all the PQMIIs would load down the 
communication network while omitting them at the ends could cause reflections resulting 
in communication errors. Install the 120Ω, ¼ watt terminating resistor and 1 nF capacitor 
externally. Although any standard resistor and capacitor of these values are suitable, these 
components can also be ordered from GE Multilin as a combined terminating network.
Each communication link must have only one computer (PLC or DCS) issuing commands 
called the master. The master should be centrally located and can be used to view actual 
values and setpoints from each PQMII called the slave device. Other GE Multilin relays or 
devices using the Modbus RTU protocol can be connected to the communication link. 
Setpoints in each slave can also be changed from the master. Each PQMII in the link must 
be programmed with a different slave address prior to running communications using the 
S1 PQMII SETUP  COM1 RS485 SERIAL PORT  MODBUS COMMUNICATION ADDRESS setpoint . The GE 
Multilin EnerVista PQMII Setup Software may be used to view status, actual values, and 
setpoints. See 4.4: Using the EnerVista PQMII Setup Software for more information on the 
EnerVista PQMII Setup Software.
FIGURE 2–13: RS485 Communication Wiring
PQM II
48
47
6
46
PQM II
GEMultilin
IED
SRSeries
GEMultilin
ProtectionRelay
RS485.CDR 
						

							CHAPTER 2: INSTALLATION
PQMII POWER QUALITY METER  – INSTRUCTION MANUAL2–19
2.2.12 RS232 Front Panel Port
A 9-pin RS232C serial port provided on the front panel allows the user to program the 
PQMII with a personal computer. This port uses the same communication protocol as the 
rear terminal RS485 ports. To use this interface, the personal computer must be running 
the EnerVista PQMII Setup Software provided with the relay. Cabling to the RS232 port of 
the computer is shown below for both 9-pin and 25-pin connectors.
FIGURE 2–14: RS232 Connection
2.2.13 Dielectric Strength Testing
It may be required to test the complete switchgear for dielectric strength with the PQMII 
installed. This is also known as “flash” or “hipot” testing. The PQMII is rated for 1500 V AC 
isolation between relay contacts, CT inputs, VT inputs, control power inputs and Safety 
Ground Terminal 6. Some precautions are necessary to prevent damage to the PQMII 
during these tests.
Filter networks and transient protection clamps are used between the control power, serial 
port , switch inputs, analog outputs, analog input , and the f ilter ground terminal 5 to f ilter 
out high voltage transients, radio frequency interference (RFI) and electromagnetic 
interference (EMI). The f ilter capacitors and transient absorbers could be damaged by the 
continuous high voltages relative to ground that are applied during dielectric strength 
testing. Disconnect the Filter Ground (Terminal 5) during testing of the control power 
inputs. Relay contact and CT terminals do not require any special precautions. Do not 
perform dielectric strength testing on the serial ports, switch inputs, analog input or analog 
output terminals or the PQMII internal circuitry will be damaged.
PQMII
PQMII
RS232.CDR 
						

							2–20PQMII POWER QUALITY METER  – INSTRUCTION MANUAL
CHAPTER 2: INSTALLATION
FIGURE 2–15: Hi-Pot Testing
746702A1.CDR
5
PQMII
POWER QUALITY METER
GE Multilin