1.16 Speed control
– with speed potentiometer PU/A
For stepless and direct control or nominal value preset of EC-fans with potentiometer input. Additionally equipped with
an enabling switch and LED-display for the operating status (dependant on feature of fan type). The potentiometer is
attached directly to the potentiometer input of the fan control. This has therefore a potentiometer supply of e.g. 10 V
DC and an input control signal of 0-10 V DC.
Basic diagram:
Example: Stepless speed control
– with universal control system EUR EC
For stepless control or adjustment of single- and 3-phase EC-fans with an input control signal of 0 - 10 V DC. Con-
nection examples of the basic diagram are mentioned further below.
Basic diagram:
Example 1: Temperature control with additional function
Example 2: Differential pressure control and air velocity
and differential temperature control
control
The use of other brands, especially other electronic devices, can lead to malfunctioning and even destruction
of controller and/or fan. Controllers which have not been cleared by Helios are not liable for warranty and
guarantee claims!
1.17 Motor protection device
All MegaBox EC centrifugal fans are equipped with an electronic temperature monitoring system for the EC motor and
electronics. This protects the motor against overloading and overheating.
If the temperature monitoring system trips frequently, this is a sign that a possible fault has occurred. The sys-
tem must not be operated and it must be investigated by a qualified electrician.
IF the permissible motor temperature is exceeded, the speed will be automatically reduced until the permissible tempe-
rature is reached and the originally set speed will be resumed after cooling
(only for types MBD EC 280 - 400).
– Integrated protective functions
The integrated protective functions cause the motor to switch itself off automatically in case of the faults described in
the following table.
EN
4
MegaBox MBW EC.. / MBD EC..
Installation and Operating Instructions
IMPORTANT
+
Fig.1
ATTENTION
m
Controlling multiple EC fans with a potentiometer
In order to control multiple EC fans above the setpoint input “0-10V”, the 10V DC voltage source must supply the
sum of all setpoint input load currents.
m
The parallel switching of +10V DC power supplies for multiple EC fans is not permitted!
Depending on the type, multiple EC fans can be controlled with the 10V DC power supply from one fan with a
potentiometer (PU/A). In this respect, consult the technical data for the control inputs and the wiring diagram SS-
1035.
If the EC power supply current is not sufficient, a sufficient (customer-supplied) 10V DC may be used (galvanically
isolated from the mains power supply).
Alternatively, the “EUR EC” module from Helios can be used for various control tasks.
WARNING
m
Fig.2
Fig.3
