Trane Flex II Series Installation Operation & Maintenance page 15

7.5 PRECAUTION FOR VERY LOW OUTDOOR TEMPERATURES
In case of installation conditions with very low temperature:
1. If there is a storage on board the unit, insert electric resistances to be calculated by:
PrWatt = V x (10 – tmin) / 860
where: PrWatt is the resistance power (Watt) and tmin is the lower temperature (°C)
2. If there is no storage, maintain the water temperature higher than 10°C by inserting thermostatic resistance
with power calculated as in case 1.
7.6 ANTIFREEZE PROTECTION ON THE HEAT EXCHANGER
Two or more protection methods should be foreseen when designing the system as a whole:
1. Continuous water flow circulation inside piping and exchanger when ambient air temperature is holding
below 5 °C. This implies what follows:
- if the water flow inside piping and exchanger of the unit is due to an external pump installed by the
customer, the on/off command of this pump must always be the one provided by the unit controller through
the relevant free potential contact in the electrical cabinet.
- as long as the ambient air temperature is holding below 5 °C the unit must always be electrically supplied.
Moreover the customer pump, if present, must always be electrically supplied alike and functioning
properly.
2. Addition of an appropriate amount of glycol inside the water circuit.
3. Additional heat insulation and sufficient heating of exposed piping.
IMPORTANT: Trane can provide various optional kits (they are not included in the Low ambient kit don to
-10°C) for the protection of all the components of the hydraulic circuit inside the unit (pumps, pipes and
tank).
4. Emptying and cleaning of the heat exchanger during the winter season.
It is the responsibility of the installer and/or of local maintenance personnel to ensure two or more of the described
antifreeze methods. Continuously verify, through routine checks, that appropriate anti-freeze protection is maintained.
Failure to follow the instructions above could result in damage to some of the unit's components. Damage from freezing
is not covered by the warranty.
CAUTION: The unit water pipes are not protected against the risk of water freeze-up when the unit is not electrically
powered and when the power and control of the external water pumps is not managed by the FLEX II unit controller.
The owner or local maintenance personnel must provide appropriate solutions to prevent freezing.
7.7 HYDRAULIC VERSIONS
Flex II units are available in six hydraulic versions characterized by complete kits of all major hydraulic components for
an easier installation, with reduced time, cost and space.
•
Stand-alone version with single pump
•
Stand-alone version with single pump and tank
•
Stand-alone version with double pump and stand-by pump
•
Stand-alone version with double pump and stand-by pump and tank
•
Modular version with single pump
•
Modular version with double pump and stand-by pump
** Flex II units can be installed in modular configuration up to a maximum of 6 units by means of a dedicated
hydraulic connection kit
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