A–22
PQM POWER QUALITY METER – INSTRUCTION MANUAL
PULSE INPUT APPLICATION
APPENDIX A: APPLICATION NOTES
A.8 Pulse Input Application
The PQM has up to 4 Logical Switch Inputs that can be configured as Pulse Input Counters.
Variables to consider when using the PQM as a Pulse Input Counter are:
•
PQM Switch Input A/B/C/D Function
•
PQM Switch Input A/B/C/D Activation
•
PQM Switch Input A/B/C/D Name
•
PQM Pulse Input (Units)
•
PQM Pulse Input 1/2/3/4 (Value)
•
PQM Totalized Pulse Input
1.
PQM Switch Input A/B/C/D Function: This parameter defines the functionality to be
provided by the PQM Switch Input. For use as a Pulse Input Counter, the PQM Switch
Input to be used must be assigned as either Pulse Input 1/2/3 or 4.
2.
PQM Switch Input A/B/C/D Activation: This parameter is set to OPEN or CLOSED. The
PQM will see the operation of the Switch Input in the state as defined by this parame-
ter.
3.
PQM Switch Input A/B/C/D Name: This parameter defines the name given to each of
the Switch Inputs used. It is used as a label only and has no bearing on the operation
of the Switch Input.
4.
PQM Pulse Input (Units): This parameter is the name given to the base units that the
PQM Pulse Input(s) will be counting. It is used as a label only and has no bearing on the
operation of the Pulse Input.
5.
PQM Pulse Input 1/2/3/4 Value: This is the value assigned to each counting operation
as determined by the Switch Input.
6.
PQM Totalized Pulse Input: This parameter creates a summing register of the various
Pulse Inputs configured. It can be configured for any combination of the PQM Switch
Inputs used as Pulse Inputs.
Application of the PQM Pulse Input(s) With a Pulse Initiator Using KYZ Ter-
minals:
Typical end receivers require a contact closure between
KY
or
KZ
based upon the type of
receiver. Because of the multi-functional parameters of the PQM Switch Inputs, the PQM
Switch Inputs are not labeled with
KYZ
markings as a dedicated pulse input device.
However, the PQM can still be used as a pulse counter. The PQM Switch Inputs require a
signal from the PQM Switch Common terminal to be activated. The PQM configured as a
Pulse Counter can be used with Two-Wire Pulse Initiators. The Pulse Initiator must provide
a dry contact operation. The Switch Common terminal of the PQM is connected to the
K
terminal of the Pulse Initiator. The PQM Switch Input assigned to count pulses can be
connected to the
Y
or the
Z
terminal of the Pulse Initiator, depending on the operation of
the Pulse Initiator, i.e. OPEN or CLOSED. The PQM Pulse Input (Value) must be assigned to
match the pulse value of the Pulse Initiator, i.e if the Pulse Initiator delivers a dry contact
closure for every 100kWh, the PQM Pulse Input (Value) must also be set to 100.
Various operating parameters with regard to the PQM Switch Inputs must be taken into
account. The PQM Switch Inputs require a minimum 100ms operation time to be detected.
The duration of the contact operation can be indefinite. The internal Switch Input circuit of
the PQM is itself switched on and off at the times when the PQM is reading the status of the
