Overload Relays; Protection Against Electro-Chemical Corrosion - Grundfos SRG.10.30.606 Montage- Und Betriebsanleitung

2 10 4 1
A1 A2
Netz
Netz 230V 40-60Hz P3VA
Rel. Ue 400V le 2.5A AC15
a
5 7
Fig. 13 Adjusting the relay
2 10 4 1
A1 A2
Netz
arnold ag
A Grundfos Company
Lecksonden Relais
Netz 230V 50-60Hz P3VA
II (2)G [EEx ib] IIC
nur für den Anschluss von Arnold AG
Lecksonden Typ AL05 Ex
Schaltpunkt
ALR 20/A Ex
SEV 05 ATEX 0131
Sonde
5 7
Sensor
Fig. 14 ALR-20/A relay connections
Do not check the leak sensor with an
ohmmeter or other measuring instruments.
Note
The leak sensor is an electronic
component.

4.5.3 Overload relays

The motor must be protected against overload via a
thermal delay relay according to local regulations.
The relay must be adjusted to the rated current
stated on the nameplate.
In the case of star-delta starting, the adjustable value
is to be I x 0.58.
N
Incorporate electro-thermal all-pole triggers in all six
mains conductors (U1, V1, W1 and U2, V2, W2).
14
3
Rel.
b
ALR 20/A
3
Rel.
CH - 6105 Schachen
Storung
1258
4.6 Protection against electro-chemical
corrosion
Two different metals or alloys cause electro-chemical
corrosion if they are connected by an electrolyte.
This applies if more than one pump is installed in the
same tank. We recommend the following additional
protection:
• galvanic separation of the earth conductor from
the neutral conductor
• galvanic separation of the mains supply by
means of an isolation transformer
• anode kit.
The earth conductor must be separated in such a
way as to ensure that no direct current can flow
through it. It must still function as a protective
conductor. This can be achieved with a limiting unit
(polarization cell or anti-parallel diode) or an isolation
transformer.
2
3
Fig. 15 Protection from electro-chemical
corrosion
Pos. Designation
1 Limiting unit
2 Earth conductor
3 Isolation transformer
When using an isolation transformer, the
Caution ratio between starting current and rated
current (I /I ) must not be altered.
A N
L1
L2
L3
N
PE
1
2