Low-Fire Only Installation - Carrier 58MVP Installation, Start-Up, And Operating Instructions Manual

FRONT
RETURN
AIR
NOTE: These furnaces are designed for a minimum continuous
return-air temperature of 60°F or intermittent operation down to 55°F
such as when used with a night setback thermostat. Return-air
temperature must not exceed a maximum of 85°F. Failure to follow
these return-air temperature limits may affect reliability of heat
exchangers, motors, and controls.
If these furnaces are used during construction when adhe-
sives, sealers, and/or new carpets are being installed, make
sure all combustion and circulating air requirements are
followed. If operation of furnace is required during construc-
tion, use clean outside air for combustion and ventilation.
Compounds of chlorine and fluorine, when burned with
combustion air, form acids which will cause corrosion of heat
exchangers. Some of these compounds are found in paneling,
dry wall adhesives, paints, thinners, masonry cleaning mate-
rials, and many other solvents commonly used in the con-
struction process.
Excessive exposure to contaminated combustion air will
result in safety and performance related problems.
Provide ample space for servicing and cleaning. Always comply
with minimum fire protection clearances shown on unit's clear-
ance to combustibles label. (See Fig. 3.) Locate furnace where
available electric power and gas supplies meet specifications on
furnace rating plate.
°F °F
MAX 85°F MIN 55°F
A93042
12
FRONT
BACK
FRONT
Do not install furnace on its back. Safety control operation
will be adversely affected. Never connect return-air ducts to
back of furnace. Failure to follow this warning could result in
fire, personal injury, or death.
32°F MINIMUM INSTALLED
AMBIENT OR FREEZE
PROTECTION REQUIRED
If these furnaces are installed in an unconditioned space
where ambient temperatures may be 32°F or lower, freeze
protection measures must be taken.
Step 2—Low-Fire Only Installation
This 58MVP furnace can be installed to operate in the low-fire
only heating mode when sized using the low-fire heating capacity.
This is accomplished by placing setup switch SW-2 in the ON
position to provide only low-fire-heat operation. See Fig. 25 and
Table 10. With this setup, high-fire operation will not occur.
When the model no. on the furnace rating plate is followed by an
asterisk (*), the furnace has an alternate low-fire only efficiency
rating as listed in the GAMA and CEC directories. This alternate
rating will be listed as the furnace model number followed by an
(-L) suffix.
B
A
C
K
A93043
A93058