MULTIFUNCTIONAL UNITS RLC – Installation and maintenance manual
MUMRLCHEAT_REV01_1012_UK
Pag. 13 di 31
After the unit has reached the final position, fix the antivibration bolts.
5.8
Precaution against frost risk of the idraulic pipes
It is necessary to insulate pipes in the plant to avoid extreme heat loss and to protect them from weather conditions. The problem of
wather pipes freezing could appear in two different situations:
Unit standby, with mode on, but electrically connected: in this case, the unit has frost resistances, which protect the wather
locally contained in the exchangers and in the pipes from ice formation. These resistances do not guarantee the protection
against the frost in the outdoor connection pipes, to be prevent by frost protection systems. Thermocold suggest to insert frost
thermostatic resistances on every outdoor pipes. In the following table there are the indicative electric power per pipe linear
meter.
nd
inch
W/mt
8
1/4"
5
10
3/8"
5
15
1/2"
5
20
3/4"
10
25
1"
13
40
1" 1/2
30
50
2"
50
65
2" 1/2
80
80
3"
120
100
4"
200
125
5"
300
150
6"
450
200
8"
750
Electrically unconnected unit: in this case the frost resistances of the unit could not guarantee the protection. So it is absolutely
necessary unload the unit content for A.C.S., instead for air conditioning it is necessary to add the correct glycol quantity
indicated in the chapter: “Ethylenic glycol correction table”.
5.9
Precaution for very low outdoor temperature
The unit has variable flow pumps on the primary circuit which allow to start with low water temperature in the storages or in the plant,
automatically, but the water temperature should not be lower than 10°C.
In case of installation conditions with a lower temperature:
1.
If there are storages, insert electric resistances to be calculated by:
Pr
Watt
= V x (10 – tmin) / 860
where: Pr
Watt
is the resistance power (Watt) and tmin is the lower temperature (°C)
2.
If there are not storages, mantain the temperature higher than 10°C the water temperature by inserting termstatic resistance
with power calculated as in case 1.
