Carrier ZONE-MIZER 50ME - Manual (Page 45)

Guide specifications
.self-contained electric cooling,
Base unit
General — Install _
natural or propane gas heating or electric cooling/electric
heating (hot water glycol heating) multizone unit(s) speci­
fically designed for rooftop installation mounted on a curb
supplied by unit manufacturer. There shall be________ zones,
each having capability to heat or cool independently of
requirements of other zones. Compressor(s) shall be
capable of unloading in steps of approximately 5 tons to
follow variations in cooling loads. Hot gas bypass shall be
used to maintain a correct minimum suction temperature at
loads below minimum compressor capacity step or between
capacity steps. Individual zone control shall not require
mixing of heated and cooled air to maintain desired space
conditions. All outdoor air for ventilation must pass thru a
cooling coil and be cooled and dehumidified whenever
mechanical cooling is operating. Unit design shall be tested
and certified by AGA. All electrical components shall be
UL listed.
Cabinet — The unit frame shall be constructed of 6000
series aluminum extrusions. Panels shall be constructed of
galvanneal steel, bonderized and finished with a baked
enamel finish. All panels requiring insulation shall be
constructed of 2 separate panels filled with polyurethane
foam insulation. All side panels shall be fastened by quick-
release compression fasteners and shall be sealed against
weather and air leakage by the use of refrigerator door type
gaskets. All top panels are to be easily and individually
removable for complete access of all components from top
as well as sides of unit and shall be fully gasketed to prevent
air and water leakage and be able to support the weight of a
250-lb man walking on top of unit. Unit shall not be over
(3 ft, 016,024,028,030) (4 ft, 034,040) above the curb height
or weigh over (4000 lbs, 016,024; 4500 lbs, 028,030; 6000 lbs,
034,040).
All utility connection openings shall be provided within
the curb enclosure. Alternate heating connection openings
shall be provided in cabinet front panel to permit installation
of shutoff device where required by local codes (48MA).
Alternate electric heating connection openings shall be
provided in cabinet front panel (50ME)
Cooling — Unit shall have a total capacity of__________ Btuh
with a sensible capacity of________ Btuh while operating at
inside conditions of______ F db and_______ F wb with a total
air quantity of______ cfm and_______cfm of outdoor air for
ventilation. Compressor power shall not exceed__________kw
at these conditions. The refrigerant circuit shall include
an accumulator, shutoff valves for compressor suction and
discharge, liquid line, and hot gas line. Filter drier and
crankcase heater(s) shall be furnished. Unit shall have
serviceable hermetic compressor(s) (one on 016, 2 on 024,
028,030,034 and 040).
Heating (48MA) — Unit shall have a heating input of
_____ Btuh. Gas furnace heat exchangers shall be manu-
■ factored of Porcelon^“. Burners shall be constructed of
stainless steel. Forced-draft combustion shall be standard.
The following safety devices shall be part of the gas heating
control circuit; main blower airflow switch, combustion air
blower flow switch, combustion chamber access door
switch, flame sensor, and heating limit switch(es). Each of
these devices must be closed, indicating a safe condition,
before gas valve can be energized. Unit shall include a
redundant gas valve with intermittent pilot ignition.
Heating (50ME) — Electric heat unit shall have a heating
capacity of_______Btuh Each zone module shall have a 2-
or 3-stage electric resistance heater assembly and include
circuit breakers, automatic resetting switches for pri­
mary thermal protection and heat limiters (fusible links) for
secondary thermal protection. Last stage of heat shall be
controlled by an adjustable outdoor air thermostat. A lock­
out circuit to keep one stage of heaters off if any module
is in cooling mode shall be provided. Hot water/glycol heat
unit shall have a heating capacity of_______ Btuh. Each zone
module shall have its own heating coil. Each heating coil
shall include an electric solenoid control valve and a
balancing valve. Bleed valves shall be provided. All zone
module heating coils shall be factory piped in parallel and
shall require no internal field piping or wiring.
.shall be Reheat humidity control in zone(s)
included by installing a humidistat in parallel with the
cooling thermostat.
Electrical controls — Unit shall be equipped with a time-
delay device to prevent short cycling of compressors and
ensure staged starting of dual compressor units. Head
pressure control down to -20 F with low-ambient starting
capabilities shall be furnished. All internal control wiring
shall be 115 volts. All external control wiring shall be 24
volts. Factory-installed circuit breakers for power and
control circuits shall be suitable for use as disconnect
switches. A 350-va, 115-volt convenience outlet shall be part
of fhe main control panel. All relays shall be the plug-in
type for reliabilify and ease of maintenance. In the event of
a main blower failure, the complete unit shall be shut down
electrically.
Filters — 41.6 sq ft of 2-in. low-velocity (qptional,
high-velocity) filters shall be used. (An optional roll filter
with 65 ft of 2-in. media shall be used.)
Outdoor air damper — Unit shall be equipped with a
modulating outdoor air damper controlled by an electric
motor and shall be adjusted by setting a rheostat
on the control panel.
Indoor air fans shall consist of (2) (3) 15-in. wheels capable
of moving_______ cfm of air against an external static
pressure of
motor shall be installed.
.in. wg utilizing .bhp. A -hp
Accessories and options
Roof curb — Install a 2-piece galvanized steel roof curb.
Condenser section shall incorporate a pitched panel for
water drainoff and a main power electrical opening. A seal
strip shall be included to seal space between unit and curb
and provide vibration isolation.
Economizer — An economizer control shall be included
which shuts off mechanical refrigeration at_______ F outdoor
air temperature and modulates outdoor air and return air
damper to maintain a mixed air temperature of_________ F.
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