Terminals 9 And 10: Pump Thermal Switches (Bimetal Switches/Klixon); Multifunctional Terminals 1, 2, 3 And 4 - Homa PCM Series Original Instruction Manual

6.3.4. Terminals 9 and 10: Pump thermal switches
(bimetal switches/Klixon)
The thermal switches of the pumps are connected to ter-
minals T/T. The function is set up in „Station parameters"
> Pumps > ATEX mode (see relevant section in HOMApp).
ATEX-Mode is not required for standard pumps.
If a thermal switch trips, the pump will switch on again
automatically after a cool-down interval.
With explosion-proof pumps, select ATEX mode in the pa-
rameter settings. The pump is permanently switched off
if a thermal switch trips. To switch it back on, let it cool
down, then press the Reset button.

6.3.5. Multifunctional terminals 1, 2, 3 and 4

These inputs can be used differently depending on the
parameter settings:
1. Parameter settings: float switch measuring system
Two different types of float switches can be connected.
1. Float switch with hysteresis (e.g. HOMA AS float
switch) or
2. Float switch without hysteresis (e.g. HOMA MS1
float switch)
Which settings to make and what to connect where?
Float switch with hysteresis (AS) Float switch without hysteresis
Connection Single station Double station
to input: preselection: 1 preselection: 2
Level 1
- -
Terminal 1
Level 2 Pump on-off Base load pump
on-off
Terminal 1
Level 3 - Peak load pump
on-off
Terminal 1
Alarm /
HW HW
high water
level
Terminal 1
24 | EngliSH
(MS1)
Single station Double station
preselection: 2 preselection: 3
Pump Both pumps off
off
Pump Base load
on pump on
- Peak load pump
on
HW HW
Level 2
Level 1
On
Peak load-
pump
Off
Base load-
On
pump
Off
AS-float switch
with hysteresis
Please note: If the float switches are installed in an
area with a potentially explosive atmosphere, they
must be connected via Zener barriers to provide an
intrinsically safe circuit.
There is sufficient space for 2 barriers in the con-
troller. If more than 2 barriers are required, install all
barriers in an external housing.
2. Parameter settings: dynamic pressure or 4-20 mA
measuring system
Terminal 1: dry-running protection float switch
A dry-running float switch can be connected to this termi-
nal, in addition to the existing dynamic pressure or 4-20
mA measuring system.
During regular operation, the input must be closed
(float switch actuated). If the input is open, the pumps
are switched off in automatic operation, the alarm LED
lights up, the yellow LEDs of the pumps flash, the buzzer
sounds and an entry is made in the fault message list.
The message must be acknowledged.
Terminals 2 and 3: seal monitoring for pump 1 and
pump 2
A potential-free „seal monitoring" contact can be con-
nected to these terminals (e.g. from electrode relay, art.
no. 1610987)
Parameter settings „without pump shutdown":
When the contact is closed, the alarm LED lights up, the
buzzer sounds and an entry is made in the fault message
list. The message must be acknowledged.
Parameter settings „with pump shutdown":
In automatic operation, the pumps are switched off when
the contact is closed, the alarm LED and the fault LED
of the relevant pump light up, the buzzer sounds and an
entry is made in the fault message list.
The message must be acknowledged.
Level 3
Level 2
Level 1
Peak load-
On2
pump
Base load-
On1
pump
Off
MB-float switch
without hysteresis
BA V2.0 01052020