Weather-Rite TT Series, Инструкция по установке, эксплуатации и обслуживанию

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TT-S
ERIES
I
NSTALLATION
, O
PERATION AND
S
ERVICE
M
ANUAL
100 of 198
(master/sla v e operation). As the VFD speeds the
b lo w er u p, the profile damper opens proportionally to
maintain the proper press u re drop across the bu rner.
As the VFD slo w s the b lo w er do w n, the profile
damper closes.
20.5.3 Two Position Volumatic
This control package allo w s the u nit to deli v er t w o Air
Vol u me req u irements, one at 100% of the u nit's
req u ired capacity, the other to b e set b et w een 25% -
100% of capacity. The method of control for this
system is an interlock contact pro
v ided b y others, or
b y contacts that is dictated b y the seq u ence of
operation.
High Air Vol u me Position
When s w itched to the High Air Vol u me position, the
discharge damper opens f u lly (100%). The bu rner
profile motor adj u sts the bu rner profile b lades to
attain proper press u re drop across the bu rner.
Lo w Air Vol u me Position
When s w itched to the Lo w Air Vol u me position, the
discharge damper opens to a setting of b et w een
25% -100% open. This position is to b e man u ally
preset b y the Minim u m Air Potentiometer w hich is
located in the air handler's control panel. The bu rner
profile motor closes the bu rner profile b lades to
pro v ide the correct press u re drop across the bu rner
for proper bu rner com bu stion. As the profile motor
closes, its motor end s w itch opens, p u tting the
Maxim u m Fire Potentiometer (located in the air
handler's control panel) into the circ u it. The
Maxim u m Fire Potentiometer red u ces the maxim u m
firing rate of the bu rner in the lo w Air Vol u me position
pre v enting the bu rner from o v er-firing.
20.5.4 Two Speed Volumatic
This control package, thro u gh the u se of a t w o-speed
b lo w er motor allo w s the u nit to deli v er t w o Air Vol u me
req u irements. One at 100% of u nit's req u ired
capacity, the other determined b y the speed of the
b lo w er motor. The method of control for this system is
an interlock contact pro v ided b y others, or b y
contacts that is dictated b y the seq u ence of
operation.
High Air Vol u me Operation
When s w itched to the high speed position, the u nit
w ill deli v er 100% of its designed airflo w . The bu rner
profile motor opens the bu rner profile b lades to attain
proper press u re drop across the bu rner.
Lo w Air Vol u me Operation
When s w itched to the lo w speed position, the b lo w er
motor s w itches to lo w speed pro v iding lo w Air
Vol u me operation. The bu rner profile motor closes
the bu rner profile b lades to pro v ide the correct
press u re drop across the bu rner for proper bu rner
com bu stion. As the profile motor closes, its motor
end s w itch opens, p u tting the Maxim u m Fire
Potentiometer (located in the air handler's control
panel) into the circ
u it. The Maxim u m Fire
Potentiometer red u ces the maxim u m firing rate of the
bu rner in the lo w Air Vol u me position pre v enting the
bu rner from o v er-firing.
20.5.5 Volumatic/Recirculatin g
This option has mod u lating inlet (optional),
mod u lating ret u rn air dampers and mod u lating
bu rner profile b lades. The Vol u matic/Recirc u lation
system is similar to the Vol u matic package bu t v aries
the mixt u re of recirc u lated air b ack into the u nit, w hile
still maintaining a constant s u pply Air Vol u me. The
inlet damper can only b e closed do w n to a minim u m
of 20% of the maxim u m capacity of the air handler
u nit, to maintain proper com bu stion. This system is
u sed w hen the total v ol u me of air s u pplied m u st b e
kept constant in order to properly distri bu te the air
thro u gho u t the bu ilding.
Methods of control for this option are b y a man u al
damper position controller (standard w ith this option)
or Space Press u re controller w hich senses the space
press u re and makes v ol u me changes as req u ired.
The minim u m air position is preset from the factory
and may b e readj u sted in the field b y the u se of the
minim u m air damper positioner, located on the air
handlers control panel. It is adj u sted to pre v ent the
air handler from going b elo w the minim u m airflo w
req u ired for proper com bu stion. The profile damper
motor w hich maintains the proper air press u re drop
across the bu rner is electrically interlocked w ith
either the optional inlet damper or the ret u rn air
damper (master/sla v e operation). If eq u ipped w ith
the optional inlet damper, as the inlet damper opens,
the profile damper opens proportionally to maintain
the proper press
u re drop across the bu rner. As the
inlet closes, the profile damper closes. If not
eq
u ipped w ith an inlet damper, as the ret u rn air
damper opens, the profile damper closes
proportionally to maintain the press
u re drop across
the bu rner. As the ret u rn as damper closes, the
profile damper opens.