Installation - Electrical
5.1 3-PHASE HOOK-UP
The HPL110A should be connected directly in front of the motor starter unit and
downstream of the motor fuses and/or isolation breaker as shown in Figure 5.1.
An external current transformer with a secondary rating of 1 or 5 amps must be used
if the rated full load motor current is in excess of 8 amps. Figure 5.1 shows correct
installation using the internal current transformer (<8A), and using an external current
transformer (>8A).
For correct readings, the current measurement must always be made on the L3 leg of the
3-phase supply. The direction of the current measurement, however, is not important.
Power-Down Alarm Blocking:
When the motor is turned off, power drops to zero and
a Min. Limit Alarm will be triggered if L2 is active. Figure 5.1 shows an auxiliary normally
closed contact on the motor starter being used to short S2 to Gnd when the motor is off.
This activates the S2 inhibit function which inhibits alarm functions and prevents a Min.
Limit alarm on power down.
An alternative method of achieving the same result is available using the Min. Alarm
Block function explained in Section 8.8; the S2 Inhibit solution described above is
preferred and safer.
Soft Starts and Frequency Inverters:
: When using the HPL110A with a soft start or
a motor driven by a frequency inverter, the HPL110A connections must be made directly
in front of these devices.
10
5
L1
L2
L3
M
3~
In < 8 Amp.
Example internal converter
Only if min. limit used
Motor
Fuses
Motor
Fuses
Aut. Reset
Ext. Reset
Aut. Reset
Ext. Reset
M
3~
In > 8 Amp.
Only if min. limit used
Example external converter
11
10
NC
NC
NC
9
C
NO
HPL110A
12
13
PE
14
S1
15
S2
1 L1
3 L2
5 L3
7 k
8 l
GND 17
NC
18
16
K
11
10
NC
NC
NC
9
C
NO
HPL110A
12
13
PE
14
S1
15
S2
1 L1
3 L2
5 L3
7 k
8 l
GND 17
NC
18
16
K
P1
P2
S1
S2
F i g u re 5 . 1
