Datasheet

Electronic monitoring relays PMDsigma
Insulation monitor
PMD s20
1001753-EN-02-2011-05Pilz GmbH & Co. KG, Felix-Wankel-Straße 2, 73760 Ostfildern, Germany
Telephone: [phone], Telefax: [phone], E-Mail: [e-mail]
Function description
Funkti onsbeschrei bung P MS s20
The insulation monitor prevents haz-
ardous insulation faults in galvanically
separated systems. The insulation re-
sistances are measured between the
network phases and the operating
earth. The measuring principle detects
symmetrical and asymmetrical insula-
tion faults.
Relay outputs (K1 and K2)
K1 and K2 operate in normally ener-
gised mode. In their default state, aux-
iliary contacts 11-14 and 21-24 are
closed and auxiliary contacts 11-12
and 21-22 are open. Normally ener-
gised mode is the default setting; this
setting can be changed via the menu.
Response resistance
If the insulation resistance falls below
the set response resistance R
an
in ei-
ther of the two measuring circuits (R
E
< R
an
), the LED "Out 1" or "Out 2" will
light and the relay contacts will de-en-
ergise.
 Response resistance Ran1:
Auxiliary contacts 11-14 will open
and auxiliary contacts 11-12 will
close (normally energised mode).
 Response resistance Ran2:
Auxiliary contacts 21-24 will open
and auxiliary contacts 21-22 will
close (normally energised mode).
Monitoring the operating earth
If the connection between the operat-
ing earth and the FE terminal is bro-
ken, contacts 11-12 and 21-22 will
close (normally energised mode).
Timing diagram
Funktionsdiagram PMD s20
Wiring
Inbetriebnahm e_Isolationswächte r
When commissioning, please note the
following:
 Output contacts 11-12-14 and 21-
22-24 are auxiliary contacts (e.g. for
a display or contactor control)
 Only wire the unit when the supply
voltage is switched off!
 Use copper wiring.
 To prevent contact welding, a fuse
should be connected before the
output contacts (see technical de-
tails).
 Ensure that the cables are laid care-
fully, because an open circuit in the
measuring circuit will cause the unit
to malfunction.
 Ensure there is adequate fuse pro-
tection on the connection cables at
terminals B1 and B2.
R
an
UB
t
t
LED
t
tr
0
1
R
ab
t
R
E
t
Reset
t
tr
tr
Auto reset
Manual reset
0
1
11
-
14
21
-
24
11
14
21 24
-
-
Hysteresis
U
B
= Versorgungsspannung/Supply voltage/Tension d'alimentation
R
an
= Ansprechwert/Response value/Seuil de déclenchement
R
ab
= Rücksetzwert/Release value/Valeur de réarment
R
E
= Isolationswiderstand/Insulation resistance/Résistance de'isolement