Pilz PMD s20 Data Sheet

Electronic monitoring relays PMDsigma

U

M

A1 A2

~

Power

B1 B2

Reset Test

G

Feedback
Earth

Y1 Y2 Y3

K1

K2

11 21

12 14 22 24

+

-

FE

Insulation monitor

PMD s20

Gertebild

Bildunterschrift

The insulation monitor monitors the in­sulation resistance of unearthed AC/
DC systems (IT systems). It meets the
requirements of EN 61557-8, IEC
60364-7-710 and DIN VDE 0100-710.

Approvals

PMD s20



Zulassungen

Unit features

Gertemerkmale

 Relay output:

2 auxiliary changeover contacts (C/
O)

 Detects symmetrical and asymmet-

rical insulation faults

 Two insulation measuring circuits
 Connection for external switch con-

tacts to trigger the manual reset
and for function testing

 Unit parameter settings are menu-

driven and infinitely variable via a
display and rotary encoder with key
function (turn and push)

 Configuration is stored on a chip

card

 Status indicators (LEDs) for:

– Supply voltage (Power)
– Insulation resistance
–Fault

Unit description

Gertebeschreibung

The insulation monitor monitors the in­sulation resistance of unearthed AC/
DC systems (IT systems). It meets the

requirements of EN 61557-8,
IEC 60364-7-710 and DIN VDE 0100­710 and may be used:

 To monitor unearthed AC/DC sys-

tems (including on board ships)

 In medical locations
 As a trip device if insulation resist-

ances are outside the permitted
range

Block diagram

Blockschaltbild

1001753-EN-02-2011-05

Electronic monitoring relays PMDsigma

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

UB = 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

Insulation monitor

PMD s20

Function description

Funktionsbeschre ibung PMS s20

The insulation monitor prevents haz­ardous insulation faults in galvanically
separated systems. The insulation re­sistances are measured between the
network phases and the operating
earth. The measuring principle detects
symmetrical and asymmetrical insula­tion faults.

Relay outputs (K1 and K2)

K1 and K2 operate in normally ener­gised mode. In their default state, aux-

Timing diagram

iliary contacts 11-14 and 21-24 are
closed and auxiliary contacts 11-12
and 21-22 are open. Normally ener­gised 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

ther of the two measuring circuits (R
< R

), the LED "Out 1" or "Out 2" will

an

light and the relay contacts will de-en­ergise.

Funktionsdiagram PMD s20

in ei-

 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

E

If the connection between the operat­ing earth and the FE terminal is bro­ken, contacts 11-12 and 21-22 will
close (normally energised mode).

Wiring

Inbetriebnahme _Isolationswäch ter

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 de­tails).

 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.

1001753-EN-02-2011-05

Electronic monitoring relays PMDsigma

L1

N

PE

1L1
1L2

E1

R

e

R

e

F1

F2

T1

Test

Y3

Reset

12

14

11

A1

A2

24

22

21

Y1

Y2

B1

B2

FE

PMD s20

Insulation monitor

PMD s20

 Only one insulation monitor should

be connected to galvanically con­nected systems.

Preparing for operation

Inbetriebnahme_Anschluss

 Supply voltage UB:

– Connect the supply voltage UB

to A1/A2. The supply voltage UB
can also be taken from the
measuring circuit.

 Measuring circuit (system to be

monitored):
– 2-phase system:
– Connect one phase of the moni-

tored system to the terminals

Application circuit AC

 A function test involving a real earth

fault (resistance) must be carried
out in order to check that the unit is
properly connected.

B1/B2 respectively.
– 3-phase system:
– Link terminals B1/B2 and con-

nect them to the system's star

point.

 Connect the output contacts in ac-

cordance with the relevant applica­tion circuit.

 Function test:

– By pressing a button at terminals

Inbetriebnahme_Anwendung_Bild_1

 Information given in the “Technical

details” must be followed.

Y1 and Y3
or

– Pressing the rotary knob for at

least 3 seconds

Leerzeilen

Inbetriebnahme

Please note:
Do not connect any cables to undesig­nated terminals.

1001753-EN-02-2011-05