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
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SECTION 21: TEMPERATURE CONTROLS
The standard temperat u re controls s u pplied w ith the
air handler are man u fact u red b y Maxitrol Company®.
The type of controls are identified b y a "series" type
The ones u sed on Weather-Rite LLC eq u ipment are;
Series 14, 44, 94 and "M".
21.1 System Overview For All Series
In descri b ing the operation of the temperat u re control
system it w ill b e red u ced to its b asic le v el.
• When a set point is selected on the dial, a
resistance v al u e (ohms) is determined. This v al u e
is sent to the amplifier.
• The discharge sensor monitoring the temperat u re
sends its resistance v al u e to the amplifier.
• The amplifier then con v erts these resistance
v al u es to a v oltage signal that its internal
components can w ork w ith. The amplifier's goal is
to ha v e a b alanced system. It does this b y
generating a mod u lating D.C. v oltage signal to the
metering v al v e.
The v oltage signal generated b y the amplifier has a
range of 0 to 30 v olts D.C. Bet w een 0 to 5 v olts is
considered to b e lo w fire w hile a b o v e 17 v olts is
considered high fire. The v oltage signal b et w een 5
and 17 v olts is the mod u lation portion of the
temperat u re control system. The metering v al v e w ill
respond to this signal b y either increasing or
decreasing the gas flo w to the bu rner. For more
detailed information, refer to the man u fact u rer's
literat u re s u pplied w ith the air handler.
The temperat u re control system components are
factory cali b rated to a b ase resistance so that
component replacement w ill not u pset the system
cali b ration. If the temperat u re control system sho u ld
req u ire field cali b ration, refer to the pro v ided
temperat u re control amplifier prod u ct information
sheet.
21.1.1 System Components For Series 14
• Temperature Selectors
These are non-temperat u re-sensing controls,
w hich are u sed to select the s u pply air
temperat u re desired d u ring heating operation. It is
generally located on the co v er of the remote panel
and is field w ired b ack to the amplifier.
• Dischar g e Sensor
This is a thermistor sensor mo u nted in a mixing or
a v eraging t ub e. It monitors the temperat u re of the
air b eing deli v ered into the discharge d u ct.
Resistance decreases as its temperat u re
increases. The sensor is located s u ch that the
a v eraging t ub e protr u des into the discharge d u ct.
NOTE : This is a field-installed de v ice and location
is critical. Make s u re this sensor in mo u nted in the
area of d u ct w ork that has the most amo u nt of air
mo v ing thro u gh it. Recommended distance from
air handler is 6 to 16 feet.
• Amplifier
This is a solid state control that recei v es its inp u t
signal from the temperat u re selectors and
discharge sensor. From this it prod u ces the
control v oltage signal that is sent to the metering
v al v e to control the discharge temperat u re of the
u nit. The amplifier is po w ered b y a 24 v olts AC
step do w n transformer.
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.