Rapid 4044, Инструкция по установке, эксплуатации и обслуживанию

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SECTION 19: E
LECTRICAL
77 of 154
located on the blo w er motor. C u rrent dra w may be
adj u sted do w n w ard by red u cing blo w er rotations per
min u te (RPM) or by increasing external static
press u re.
19.5 Control Current Draw
The maxim u m c u rrent dra w for an air handler’s
controls and accessories is 3A.
19.6 Safety Systems
Safety systems are req u ired for proper performance
of the air handler. The air handler shall not be
permitted to operate
w ith any safety system disabled.
If a fa u lt is fo u nd in any of the safety systems, then
the system shall be repaired only by a contractor
q
u alified in the installation and ser v ice of gas fired
heating eq u ipment, u sing only components that are
sold and s u pplied by Rapid Engineering LLC. Refer
to Page 81, Table 31 for a brief description of each
safety de v ice, its location and its s w itching v oltage.
Table 30: Safety Systems
19.6.1 Manual Reset Hi g h Temperature Limit
Switch
If for any reason, the temperat u re of the air at the
discharge of the blo w er reaches the limit set point of
160° F (71.1° C), the high temperat u re limit s w itch w ill
open the circ u it to the b u rner system and discontin u e
all b u rner f u nctions. E v ents that co u ld res u lt in
excessi v e discharge air temperat u res incl u de if the
b u rner mod u lation amplifier is defecti v e (i.e.
temperat u re sensor goes open circ u it) or if a s u rge in
gas press u re reaches the b u rner. Restarting of the
b u rner can only be accomplished after the limit has
cooled do w n and the reset b u tton on the s w itch has
been depressed. This s w itch is located on the blo w er
ho u sing inside the air handler.
19.6.2 Pressure Switches
The lo w airflo w v elocity press u re s w itch monitors the
airflo w (differential press u re) across the b u rner.
When the airflo w across the b u rner reaches the
proper v elocity ( v ol u me) for comb u stion, the s w itch
closes. When the s w itch closes, it permits the flame
safeg u ard relay to begin ignition. This s w itch is
factory set at 0.32 in w c (0.8 mbar). The high v elocity
press u re s w itch w ill open if the airflo w across the
b u rner reaches its maxim u m allo w able limit. This
s w itch is factory set at 1.40 in w c (3.5 mbar). The
press u re s w itch is a safety de v ice, w hich cannot be
field-adj u sted or tampered w ith.
19.6.3 Gas Pressure Switches
Gas press u re s w itches are standard on certain
models (FM compliant gas trains abo v e 2,500 MBH
and XL compliant gas trains) and are also a v ailable
as an option on the others.
The f u nction of the gas press u re s w itches is to
protect against ins u fficient, lack of gas press u re and
excessi v e press u re in the system.
On the lo w gas press u re s w itch side, this s w itch
opens its internal s w itch w hich sh u ts the b u rner do w n
and pre v ents its operation d u e to ins u fficient gas
press u re.
On the high gas press u re s w itch side, its internal
s w itch w ill open, sh u tting do w n the b u rner d u e to
excessi v e gas press u re passing thro u gh the gas
train.
The settings of the gas press u re s w itches are field
adj u stable. The one monitoring the incoming gas
press u re is the lo w gas press u re s w itch. The lo w gas
press u re s w itch m u st be set to the minim u m req u ired
gas press u re as indicated on the data plate.
The high gas press u re s w itch m u st be set to 1 in w .c.
(2.5 mbar) abo v e high fire setting established d u ring
commissioning.
The s w itch w ill ha v e to be reset man u ally, once the
condition has been corrected.
Safety Controls Location Volta g e
Man u al Reset High-
Temp Limit (All Models)
Blo w er Discharge 120
Press u re S w itches
(All Models)
Air Handler Control
Enclos u re
120
Flame Control
(2010/2010B/2020/2030) Air Handler Control
Enclos u re
120
Flame Control (2005)
Air Handler Control
Enclos u re
24
Discharge Temperat u re
Monitor (All Models)
Blo w er Discharge 24
AM Resistor
(AM/VAV Style) Air Handler Control
Enclos u re
24