Options Installation - Lennox CMC 020S Installation, Operating And Maintenance Manual

2.- INSTALLATION

2.8.- OPTIONS INSTALLATION

ELECTRICAL HEATER
The electrical heater must be supplied
from the unit's electrical box.
HOT WATER COIL
PROTECTION AGAINST FREEZING:
• Use glycol water. GLYCOL IS THE ONLY EFFECTIVE
PROTECTION AGAINST FREEZING.
This kit includes a safety thermostat with a probe located inside the
hot water coil. When the temperature drops below 4ºC, the unit will
stop in order to protect the hot water coil and to prevent the unit from
working with very low evaporating temperatures.
Five wires must be added between indoor and outdoor unit with this
option.
Hot water coil includes regulating valve:
- ON/OFF for standard version.
- Proportional (0-10V).
You must ensure that manual or automatic air vents have been installed on all high points in the system. In order to
drain the system, check that drain valves have been installed at all low points of the system.
A HEATING COIL FROZEN DUE TO LOW AMBIENT CONDITIONS IS NOT COVERED BY THE WARRANTY.
FREE COOLING
1.- OPERATION
The control compares the values of temperature/enthalpy between outside air and room air by means of the probes;
if there is a negative difference and the safety elements allow (discharge temperature probes) then the control acts
on the servomotor, which opens the outside damper and closes the return damper, allowing cool outside air to enter
the room.
The damper is proportionally regulated.
If there is not a great demand for air indoors, it may be enough just to have free cooling to condition the room. If there
is a greater demand for air, the free cooling and the unit may need to be working in different cooling mode stages.
2.- SUPPLY AND INSTALLATION
The free cooling option can be delivered as a packaged system or as a split system.
The mixing section will be delivered with the unit for models 020S to 045D and as a split system for the remaining models.
Return fan section will be delivered with the unit.
Confi guration of free cooling supply:
INDOOR
020S-045D
UNIT
EF: Exhaust fan.
MS: Mixing section.
RS: Return fan section.
Small panel for contactors
and connections
Location of the
electrical heater once
055D-085D
MS IU
EF
IU: Indoor unit.
Flexible duct to be installed by the customer.
* Mixing and return fan sections can be together or not.
Safety
thermostat
installed
Support
Location of the hot
water coil once
installed
*
MS
IU
EF
23
Water outlet
Water inlet
Support
*
055D-085D
RS
*
MS IU