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IV Continuous product development may give rise to specification changes without notice.

2014-11-04

2 (2)

Product sheet

Operation and Maintenance

Flexomix MIE-EL

Operation and Maintenance  

Instructions

The heating coil consists of “unsheathed” electric 
heating rods. A substantial accumulation of dust or 
other impurities on the heating rods will cause them 
to overheat. This could shorten their service life. This 
might also entail an odour of burnt dust and in the 
worse case, the risk of fire. 

Overheated electric heating rods may become 
deformed or loosen from their suspension fasteners 
and heat the air unevenly.

Inspection

Check that the electric heating rods are correctly posi-
tioned and that they are not deformed in any way.

Cleaning

Vacuum or wipe surfaces with a moist cloth to remove 
any dust or impurities.

Function

1.  Simulate reduced required output by temporarily 

lowering the temperature setting (setpoint), so that 
all the electric output steps (contactors) switch out.

2.  Then sharply increase the setpoint setting and 

check that the electric output steps switch in.

3.  Restore the temperature setting.

4.  Stop the air handling unit (NB: Do not break the 

circuit with the safety switch). All the electric 
output steps should switch out (i.e. the contac-
tors in the OFF position). Stopping the unit may 
be delayed approximately 2–5 minutes to allow 
the fans to cool the heat energy stored in the air 
heater.

The electric heater is equipped with dual temperature 
limiters. The one that resets itself automatically should 
be set to 70 °C.

The overheat protection with manual reset interrupts 
operation when the heater reaches approximately 
120°C and is located on the cover panel on the side 
of the heater. 

Determine the cause of overheating 

and take corrective action before you reset the 

protection device.

Please note that the risk of overheating increases as 
the air flow through the unit decreases. The air speed 
should not be lower than 1.5 m/s.

Wiring instructions

Electric heater without control system (HT)

Ø 1
Ø 2

Overheat protection with automatic reset.

Ø 3
Ø 4

Overheat protection with manual reset.

Ø 5
Ø 6

Ø 7

Connecting the first step: 0,2-3,5 kW 2-phase 400 V.

NB: For output power > 3.5 kW the first step is 3-phase 400 V.

Ø
Ø
Ø

Connecting the second step: 3.6-43 kW 3-phase 400 V

Ø
Ø
Ø

Connecting the third step: 3.6-43 kW 3-phase 400 V

Ø
Ø
Ø

Connecting the fourth step: 3.6-43 kW 3-phase 400 V

Output steps to be connected sequentially, beginning at  
terminal no 5.

If any output group exceeds 43 kW, it must be divided into 
two groups of an equal size.

 

Electric heater with integrated control (HS)

 

Y

G0

PE

L3

L2

L1

L

N

PE

+

1
2
3
4

NC

NO

POWER SUPPLY

3×400V~

CONTROL

0-10V=

OPERATION

1×230V~

ALARM (CLOSES 
BETWEEN 3-4 IN 
EVENT OF ALARM)

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