Rapid 2005, Инструкция по установке, эксплуатации и обслуживанию

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B-S
ERIES
I
NSTALLATION
, O
PERATION AND
S
ERVICE
M
ANUAL
108 of 147
SECTION 1 8 : SEQUENCE OF OPERATION
1 8 .1 Air Handler Confi g uration
Based on the air handler application, the air handler
may be config
u red in any of the fo u r styles described
in the u pcoming sections. These config u rations are
a v ailable on all air handlers, except the 2005 w hich is
only a v ailable in the MUA style. For a comparison of
these config u rations, See Page 109, Table 17 and
Page 109, Figure 71 .
1 8 .1.1 Make-Up Air (MUA) Style
The MUA style air handler has a constant speed
blo
w er that is designed to deli v er a constant v ol u me
of air to the heated space. This style air handler
s
u pplies 100% o u tside air to the heated space and is
not capable of s u pplying ret u rn air.
1 8 .1.2 Fixed Recirculation (FR) Style
The FR style air handler has a constant speed
blo
w er that is designed to deli v er a constant v ol u me
of air to the heated space. In all cases, ho w e v er, the
air being deli v ered directly o v er the b u rner for
comb u stion m u st al w ays be 100% o u tside air. The air
handler deli v ers 20% o u tside air and 80% of ret u rn
air. The o u tside air is heated then mixed w ith the
ret u rn air prior to being deli v ered to the heated
space.
1 8 .1.3 Air Mana g ement (AM) Style
The AM style air handler has a constant speed
blo
w er that is designed to deli v er a constant v ol u me
of air to the heated space. A b u ilding press u re sensor
is u sed to detect the differential press u re bet w een
the o u tside and the heated space. The total v ol u me
of air deli v ered by the air handler may at times
consist of 0% to 80% ret u rn air. An a u tomatic control
is pro v ided for the o u tdoor air and ret u rn air dampers.
A n u ll press u re s w itch is u sed to sense a positi v e
space press u re (room or d u ct). This n u ll press u re
s w itch is mo u nted in the control enclos u re. More or
less o u tdoor air is bro u ght into the space to satisfy
the press u re setpoint. Most installations req u ire a
setpoint of 0.02 in w c to 0.03 in w c to achie v e
adeq u ate press u re control in the b u ilding space. 5/
16" diameter t u bing connected to the positi v e
press u re port of the s w itch m u st r u n to the inside of
the b u ilding. 5/16" diameter t u bing connected to the
negati v e press u re port of the s w itch m u st r u n to the
o u tside of the b u ilding.
1 8 .1.4 Variable Air Volume (VAV) Style
The VAV style air handler u ses a b u ilding press u re
sensor to detect differential press u re bet w een the
o u tside and the heated space. The air handler w ill
deli v er 100% o u tside air and w ill not deli v er ret u rn air.
The air handler w ill ens u re proper air v elocity o v er
the b u rner by u sing a photohelic air sensor to
meas u re the press u re drop across the b u rner and by
u sing a damper to modify the airflo w w hen a
press u re change is req u ired. A second photohelic air
press u re sensor is u sed to meas u re the differential
press u re bet w een the o u tside and the heated space.
Most installations req u ire a setpoint of 0.02 in w c to
0.03 in w c to achie v e adeq u ate press u re control in
the b u ilding. The second press u re sensor is u sed to
pro v ide a control signal to the v ariable freq u ency
dri v e that, in t u rn, controls the blo w er speed. 5/16"
diameter t u bing connected to the positi v e press u re
port of the press u re sensor m u st r u n to the inside of
the b u ilding. 5/16" diameter t u bing connected to the
negati v e press u re port of the press u re sensor m u st
r u n to the o u tside of the b u ilding.
DANGER
Electrical Shock Hazard
Disconnect electric before service.
More than one disconnect switch may be
required to disconnect electric from
equipment.
Equipment must be properly grounded.
Failure to follow these instructions can result
in death or electrical shock.
WARNING
Carbon Monoxide Hazard
Do not recirculate air from the heated space
over burner.
Air supply to burner must be from outside.
Failure to follow these instructions can result
in death or injury.