Post-Heater - Zehnder Option Box Manuel De L'installateur

If the connection with the sensor of the ComfoFond-L
is lost the ventilation unit will turn the ComfoFond-L off
and give the error GROUND_HEAT_CONNECT_ERROR
on the display of the ventilation unit.

9 Post-heater

The device is equipped with an optional
control for a post-heater to (pre)heat the
supply air.
If the house has very limited thermal losses
(e.g. passive house), the post-heater may
be the only active source to heat the house.
a post-heater can be used to prevent for sense of
draught.
Installation
The device supports electrically controlled post-heaters
with 0-10V input. PWM (Pulse Width Modulation) input is
not supported.
The device is only for the control of a post-heater and
does not deliver the needed 230V power supply for the
post-heater.
Only a post-heater with SELV 0-10V
may be used. This means the power
supply of the post-heater must be
double insulated from the sensor and
0-10V control. The device also does not
provide any safety controls such as a
high temperature thermal cutoff.
1. Install a NTC temperature sensor (10k @ 25°C) after
the post-heater in the supply air to connector 7a (see
the wiring diagram).
2. Install the 0-10V control of a post-heater to connector
7b (see the wiring diagram).
3. Make sure the post-heater is equipped with a high
temperature thermal cutoff.
4. Install the power supply of the post-heater to a
different group in the fuse box than the ventilation
unit.
24 - EN
Commissioning
After installation, commission the post-heater in the
ventilation unit OPTION BOX SETTINGS menu.
The following menus must be set:
Menu item
PROPORTIONAL BAND
(Default = 10ºC)
INTEGRAL TIME
(Default = 180s)
The default settings have been optimized for electrical
5
Otherwise
postheaters of (CV-MPX 200) 2.4kW and should be
acceptable for electrical post-heater between 0.5kW and
3.6kW.
The higher the value of the proportional band, the less
immediate response to an error. The lower the value,
the less stable the response to measurement errors. If
instabilities occur at stable setpoints (no changes), the
proportional band should be doubled.
The higher the value of the integral time, the slower
the response to errors in time. If instabilities occur to
setpoint changes, the integral time should be doubled.
In chapter "Proportional Integral Differential (PID)
controller" you can find more information on the
proportional band and integral timer.
Operation
The ventilation unit will control the 7b (control signal)
connector from the information received with the 7a
(temperature sensor) connector and the setpoint.
The first two minutes after powerup of the ventilation
unit the temperature sensor has not reached the actual
temperature yet to know if the post-heater needs to
be turned on. Therefore the post-heater will remain off
for at least the first two minutes after powerup of the
ventilation unit.
The end user can influence the behaviour of the post-
heater by means of setting a control mode, a timer and/
or a comfort profile. You can find information on the
possibilities in the user manual of the ventilation unit.
If the connection with the sensor of the post-heater is
lost, the ventilation unit will turn the post-heater off and
give the error POSTHEAT_ CONNECT_ERROR on the
display of the ventilation unit.
Function
The proportional band value, which the
ventilation unit must use in its calculations
for the output signal.
The integral time value, which the
ventilation unit must use in its calculations
for the output signal.
5
Must be determined by the installer of the heating system.