Precautions; Operating Limits; Clearances Required; Receiving A Shipment - Installation Methods - Carrier 42EM Series Installation, Operation And Maintenance Instructions

1 - PRECAUTIONS

1.1 - Operating limits

1.1.1 - Cooling mode
Minimum supply air temperature 12°C when the unit is
installed where the ambient temperature is 27°C dry bulb
with 65% relative humidity.
In steady state, the ambient conditions shall not exceed
27 °C dry bulb temperature and 65% relative humidity.
1.1.2 - Heating mode
Max. supply air temperature = 60°C to avoid damage of
the discharge spigots. To avoid all risks of stratification,
Carrier recommends to keep the supply air temperature
below 35°C.
1.1.3 - Operating environment
The 42EM has been designed for indoor application in
'urban' conditions having a non-corrosive, dust-free and
non-marine environment.
The concentrations of the following chemicals must not be
exceeded in any event:
• SO < 0.02 ppm
2
• H S < 0.02 ppm
2
• NO, NO < 1 ppm
2
• NH < 6 ppm
3
• N O < 0.25 ppm
2
Do not install a unit where flammable gases or products of
an acidic or alkaline character may be present. The copper/
aluminium coil or components inside the unit could suffer
irreparable corrosion damage in their presence.
1.1.4 - Recommended coil water quality
At installation handover, and then periodically every year,
it is advised to analyse the water for bacteria (detection of
ferro-bacteria, H S-producing and sulphate-reducing
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bacteria) and chemicals (in order to avoid problems due to
corrosion and scaling).
The water circuit must include all the necessary elements for
the treatment of the water: filters, additives, intermediate
exchangers, purges, drains, isolating valves, etc., according
to the analysis results.
The results must be in accordance with the values shown
below:
• Total hardness in mmol/l:
• Chloride [CL ]
-
• Sulphate [SO ]
2-
4
• Nitrate [NO - ]
3
• Dissolved iron:
• Dissolved oxygen:
• Carbon dioxide [CO ]
2
• Resistivity:
• pH:

1.2 - Clearances required

Without return air plenum: Fig. 1
With return air plenum: Fig. 2
1 < mmol/l < 1.5
< 10 mg/litre
< 30 mg/litre
= 0 mg/litre
< 0.5 mg/litre
4 < [O ] < 9 mg/litre
2
< 30 mg/litre
20 Ohm·m < Resistivity
< 50 Ohm·m
6.9 < pH < 8

1.3 - Receiving a shipment - installation methods

When receiving a shipment, check the condition of the goods
and report any damage in transit to the shipping company.
Do not unpack the units until just before they are due to
be installed, and make sure they are as close as possible to
the installation site when unpacking them. Do not place
heavy articles of any sort on them.
1.4 - Supply voltage 230 V ± 10% - 50 Hz
Check that the supply voltage and frequency correspond
to the values of the unit to be installed.
WARNING: Failure to take proper account of the above
advice and unauthorised modification of the electrical
connections will render the Carrier warranty on the
product null and void.

2 - SAFETY CONSIDERATIONS

WARNING: Switch off the main electrical power supply
to the unit and accessories (if installed) before doing any
work on the unit.

2.1 - General

Installing, commissioning and servicing of the various
component (unit, control system, hot and cold water
system, air distribution system) can be dangerous unless
certain aspects of the installation, such as the presence of
mains electricity and hot or cold water in the air
conditioning equipment, are taken into account. Only
specially trained and qualified technicians and installers
who have been fully trained on the product concerned are
authorised to install, commission and service this
equipment.
During servicing work, it is essential to apply all recommen-
dations and instructions given in service leaflets, on labels
or in the instructions delivered with the equipment, and to
comply with any other relevant instructions.
Definition of the pictograms used:
• Electrical danger - Fig. 3
• Caution hand hazard - Fig. 4
• General danger - Fig. 5
Comply with all safety rules and regulations currently in
force. Wear eye protectors and work with hand gloves and
any individual protection equipment following local
legislation. Take care when moving or positioning of the
equipment.

2.2 - Protection against electrocution

Only electricians qualified to the level recommended by the
IEC (International Electrotechnical Commission) in its
standard IEC 364, corresponding to Europe HD 384, France
NFC 15 100 and UK IEE Wiring Regulations, may have
access to electrical components. In particular it is obligatory
to disconnect all power supplies to the unit and its accessories
before carrying out any work. Disconnect the main power
supply with an isolating device (not supplied by Carrier).
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