Eng
lish (US)
12
7.2 Gearbox protection
The gearbox is monitored for the ingress of water by a leak
sensor incorporated in the gearbox.
If the monitoring function is required, the leak sensor must be
connected to a Grundfos relay, type ALR 20. If the gearbox/shaft
seal housing is not monitored for the ingress of water, it is
recommended to make inspection every 6 months. If oil is
contaminated by water replace shaft seal.
For longer distance, use an additional, screened cable.
An external alarm indicator, if any, must be connected to the
potential-free outputs, terminals 1 and 3 or 4, respectively.
Maximum load: 250 V, 5 A.
Leak sensor
•
Two conductors (terminals 21 and 22).
•
Operating voltage: Approx. 12 V.
•
Current: 1 to 10 mA.
To adjust the sensitivity of the ALR-20/A relay, proceed as
follows:
1. Turn adjusting screw (pos. a) on the relay until indicator light
(pos. b) illuminates.
2. Turn the adjusting screw in the opposite direction until the
indicator light goes out.
3. Continue to turn the adjusting screw 60 °
(same direction as in step 2).
Fig. 14 Adjusting the relay
Fig. 15 ALR 20 relay connections
7.3 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.
Electro-thermal all-pole triggers in all six mains conductors
(U1, V1, W1 and U2, V2, W2).
7.4 Starting method
In general it is advisable to use Soft-start or Variable speed drive,
in order to lower wear and tear on the equipment.
Continuous operation
The SRP recirculation pumps can be started via direct starting.
Intermittent operation
The SRP pump can be started via direct starting, prerequisite that
the maximum number of start per hour is not exceeded. In order
to limit wear and tear on the equipment, it is recommended that
the SRP pump has to be started using either Soft-starter or
Variable speed drive.
Note
Note
The cable between the relay and the pumps must
be maximum 164 ft (50 m).
T
M
02
88
66
09
0
4
ALR 20/A
5
7
Netz 230V 40-60Hz P3VA
Rel. Ue 400V le 2.5A AC15
2
10 4
1
3
A1 A2
Netz
Rel.
a
b
TM
03
20
60
35
05
Note
Note
Do not check the leak sensor with an ohmmeter
or other measuring instruments. The leak sensor
is an electronic component.
2
10
4
1
3
A1
A2
arnold ag
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
Storung
ALR 20/A Ex
SEV 05 ATEX 0131
1258
5
7
Sonde
Rel.
Netz
CH - 6105 Schachen
A Grundfos Company
Sensor
L
N
5 A
2
50 V
