VALLOX 252 M
9
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
temperature sensor, thereby preventing the heat recovery cell from free-
zing. 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 heating unit. 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.
Control of Operation
The ventilation unit can be stopped by the fan speed switch on the manual
control unit.
Fan Speed Adjustment
The users can control the fan capacity of the ventilation unit in two steps
using the speed selection switch on the manual control unit (H) in the
ventilation zone.
Supply Air Temperature
A regulating valve (not included in the VALLOX 252 M delivery) directs
the operation of the LP2 post-heating unit on the basis of the measurement
data given by the thermostat sensor in the supply air duct. The aiming is to
keep supply air temperature at the temperature value set with the regula-
ting valve (10...25 ˚C)
Heat Recovery Bypass
Heat recovery can be bypassed using the Summer / Winter switch on the
manual control unit (H).
When the switch is in the Winter position, heat recovery is on. The
Summer position bypasses heat recovery and deactivates the preheater
(LP1), if preheating is used.
DESCRIPTION OF OPERATION VALLOX 252 M VKL MANUAL CONTROL UNIT
Parts List
Code
Name
Technical details
Note!
Equip-
Delivery
(factory settings in parentheses)
ment
responsibility
FG
Damper motor
Automatic heat recovery bypass 24V, 2W, 8Nm
Standard
X
IU
H
Manual control unit
Fan speed adjustment,
control of heat recovery bypass
Standard
X
IU
LP1
Preheater
Electric radiator 2.5kW
Options
IU
LP2
Post-heating unit
Water radiator 5kW, 70/50 ˚C
Options
IU
LTO1
Heat recovery cells
2-step, = 70 %
Standard
X
IU
LTO2
PF
Discharge air fan
qv = 230 dm3/s (100Pa)
Standard
X
IU
SU
Filter
Supply air EU7, discharge air EU5
Standard
X
IU
SV
Regulating valve
Self-operating radiator thermostat
Not included in the
ventilation unit delivery
TS1
Temperature thermostat
Discharge air temperature
Heat recovery defrosting
Adjustment range -2...6 ˚C (2)
Standard
X
IU
TS5
Temperature thermostat
Discharge air temperature
Preheating, electric
Adjustment range -0...8 ˚C (2)
Standard
X
IU
TF
Supply air fan
qv = 210 dm3/s (100Pa)
Standard
X
IU
TZ1
Overheat protector of the electric radiator
Automatic reset (+60 ˚C)
Included in LP1 / LP2
IU
TZ2
Overheat protector of the electric radiator
Manual reset (+95 ˚C)
Included in LP1 / LP2
IU
FGU
Damper motor
Damper motor in the outdoor air duct
(spring return) 24VAC
IU
FGJ
Damper motor
Damper motor in the extract air duct
(spring return) 24VAC
IU
