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Type PM Line of Relays For Pilot Wire Monitoring
And Transferred Tripping
RELAY
PMA OR PMA-1
PMD OR PMD-1
†
PM-5
PMG-13 OR PM-13
PM-23 OR PM-2 & PM-3
†
Same relay as for three-terminal lines
‡
These are pilot-wire current values
NOMINAL CALIBRATION VALUES - THREE TERMINAL LINE
RELAY
PMA OR PMA-1
PMD OR PMD-1
†
PM-5
PMG-13 OR PM-13
PM-23 OR PM-2 & PM-3
†
Same relay as for two-terminal lines
‡
These are pilot-wire current values
5.2
PMA, PMA-1, PMG-13 AND PM-13 RELAYS
Select the transformer tap nearest to expected nor-
mal ac supply voltage. The full wave rectifier is con-
nected to a secondary transformer tap. Where
desired, the output voltage can be raised about 5%
by reconnecting across the full secondary winding.
5.3
INDICATING CONTACTOR SWITCH
No setting is required on the ICS unit except the selec-
tion of the 0.2 or 2.0 ampere tap setting. This selection
is made by connecting the lead located in front of the
tap block to the desired setting by means of the con-
necting screw. When the relay energizes a type WL
relay switch, or equivalent, use the 0.2 ampere tap.
6.0 INSTALLATION
The relays should be mounted on switchboard panels or
their equivalent in a location free from dirt, moisture,
excessive vibration, and heat. Mount the relay vertically
by means of the four mounting holes on the flange for
semi-flush mounting or by means of the rear mounting
stud or studs for projection mounting. Either a mounting
stud or the mounting screws may be utilized for ground-
ing the relay. The electrical connections may be made
NOMINAL CALIBRATION VALUES - TWO TERMINAL LINE
LOW CURRENT ALARM
0.65 mA
0.65
-
0.65
†
0.65
LOW CURRENT ALARM
†
Table 4:
1
HIGH CURRENT ALARM
‡
Table 5:
HIGH CURRENT ALARM
0.7 mA
0.7
-
‡
0.7
0.65
directly to the terminals by means of screws for steel
panel mounting or to the terminal studs furnished with the
relay for thick panel mounting. The terminal studs may be
easily removed or inserted by locking two nuts on the
stud and then turning the proper nut with a wrench.
For detailed FT case information, refer to Instruction
Leaflet 41-076.
Where the potential to ground impressed on the
relays can exceed 700 volts, a drainage reactor in
conjunction with its surge protectors, or the reactor in
conjunction with 700 volt carbon-block arresters, is
recommended. For details, see Protection of Pilot-
Wire Circuits, AIEE Committee Report, paper 58-
1190, AIEE Transactions, 1959, Volume 78, Part III B
pp. 205-212. Also, see AIEE Special Publication S-
117, Applications and Protection of Pilot-Wire Cir-
cuits for Protective Relaying, July 1960.
7.0 ADJUSTMENTS AND
MAINTENANCE
The proper adjustments to insure correct operation of
this relay have been made at the factory and should
not be disturbed after receipt by the customer. If the
2
TRIP
1.3mA
1.3
±0.3
‡
14 V
1.3
14 V
-
1
Left-Hand Contact
2
Right-hand Contact
TRIP
2.3mA
2.3
±0.3
‡
14 V
2.3
14 V
-
41-973.5R
-
-
-
-
-
-
7
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