Vallox 252 M Manual Download

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VALLOX 252 M

Heat Recovery Defrosting

The TS5 temperature thermostat directs the operation of the preheater
(LP1) on the basis of the measurement data supplied by the temperature
sensor, preventing the risk of freezing and the stopping of the supply air
fan (TF). If the capacity of the preheater (LP1) is not sufficient, or if there is
no preheater, the TS1 defrosting thermostat of the heat recovery cells stops
the TF supply air fan on the basis of the measuring data on the temperatu-
re sensor, thereby preventing the heat recovery cell from freezing. As
soon as the risk of frosting passes, the fan restarts automatically. The
threshold temperature for defrosting (-2…+6 ˚C) and the difference area
(2 ˚C) can be set on the thermostat.

Overheating Protection of the Heating Unit

Overheat protection thermostats TZ1 and TZ2 monitor the surface tempe-
rature in the LP1 and LP2 heating units. If surface temperature exceeds the
threshold, overheat protection is triggered and power supply to the hea-
ting unit is stopped. The TZ1 overheating protector is reset automatically,
and the TZ2 protector manually.

Damper Motors of the Outdoor and/or Extract Air Ducts

The spring return damper motors (24VAC) that may be installed outside
the ventilation unit, in the outdoor or extract air ducts, can be controlled
with control voltage (24 VAC) coming from the ventilation unit: when the
ventilation unit is stopped, also the control voltage fed from the unit is
stopped.

Alarms

The PDS1 and PDS2 pressure difference switches monitor the pressure
difference on the supply and discharge air sides. If the pressure difference
grows too large because of dirty filters or clogged ducts, remote monito-
ring receives potential free operation mode information from the unit.

Control of Operation

If needed, the ventilation unit can be stopped by controlling the contac-
tors in the unit (Min., 1/2, Max.) or by controlling power supply via the
contactor in the distribution panel.

Fan Speed Adjustment

The ventilation unit can feed control voltage (24VAC) to the remote moni-
toring center, and the remote monitoring center can then direct the fan
capacity of the ventilation unit in three steps according to the control
signal (24VAC) received by the Min., 1/2, and Max. contacts in the
connection box. Remote monitoring receives potential free operation mo-
de information on the mode selected (Min., 1/2, Max.).

Supply Air Temperature

The control / adjustment center of the unit directs the operation of the
post-heating unit (LP2) on the basis of the measuring data on the sensor of
the TS2 temperature thermostat, aiming at keeping supply air temperatu-
re at the temperature value set with the TS2 thermostat (10…25 ˚C).

Heat Recovery Bypass

With the help of control voltage (24VAC) fed from the ventilation unit to
the remote monitoring center and its control functions, the heat recovery
bypass function can be directed according to the control signal (24 VAC)
received by the NC contact in the connection box. When heat recovery
bypass is activated, the preheater (LP1), if used, and the post-heating unit
(LP2) are deactivated.

DESCRIPTION OF OPERATION DIAGRAM VALLOX 252 M REMOTE MONITORING CONTROL

Parts List

Code

Name

Technical details

Equip-

Delivery

(factory settings in parentheses)

Note!

ment

Responsibility

Damper motor