Reznor DV Operation Manual (for units built before August 2003) User Manual
Page 13
Form
O-DV/RDF/ADF, P/N 148385, Page 12
FIGURE 20 - Modulating
Gas Valve
FIGURE 18 - Two-Stage
Gas Valve and Discharge
Ductstat in Makeup Air Gas
Control System, Option
AG3
FIGURE 19 - Mechanical
Modulation Gas Valve in
Makeup Air Gas Control
System, Option AG49 and
Option AG50
troller that monitors discharge air temperature. The controller has a built-in
setpoint selector from 0° - 100°F.
Due to different CFM settings and outside temperatures, the average down-
stream outlet temperature may not match the control setting exactly. After the
installation is complete, adjust the setpoint to achieve the desired average out-
let air temperature. See the valve manufacturer's literature provided in the
owner's envelope for specifications, wiring, and operating information.
Two-Stage Gas Valve for Makeup Air (Option AG3)
(750 MBH maximum)
The single-stage valve is replaced by a two-stage valve having low fire and
high fire operation. The two-stage valve is controlled by a unit-mounted duct-
stat that monitors discharge air temperature. The ductstat has a built-in setpoint
selector from 60°-110°F. Available for use with natural gas only.
Due to different CFM settings and outside air temperatures, the average down-
stream outlet temperature may not match the ductstat setting exactly. After the
installation is complete, adjust the setpoint of the ductstat to achieve the de-
sired average outlet air temperature. See the valve manufacturer's literature
provided in the owner's envelope for specifications, wiring, and operating in-
formation.
Mechanical Modulation for Makeup Air (Option AG49,
40-160°F, or AG50, 40-120°F) (750 MBH maximum)
The mechanical modulation valve regulates the flow of gas based on the de-
mands of the sensing bulb which is located in the discharge airstream.
See the valve manufacturer's literature provided in the owner's envelope for
specifications and operating information. Available for use with natural gas
only.
Electronic Modulation Gas Control for Makeup Air (100%
Outside Air), Options AG30, AG31, AG32, AG33, AG35, AG36
Refer to the wiring diagrams in the main electrical box to determine which
controls are on the system being serviced. NOTE: All field-supplied control
wiring for Maxitrol controls must not be run inside conduit with line voltage
wiring. To avoid any potential electrical interference, all field-supplied wiring
for Maxitrol controls should be shielded wiring and must be grounded at the
unit only.
Function: These gas control systems provide heated makeup air at a tempera-
ture controlled by a discharge air sensor. Makeup air gas controls apply only
to systems with 100% outside air. Each system is equipped with electronic
modulation controls that modulate burner flame from 1/25th of full fire input
to full fire.
The electronic modulating-type gas controls act in response to discharge and/
or room air temperature sensors to change the gas flow rate to the burner, thus
12. Gas Train (cont'd)
Makeup Air (100%
Outside Air) Gas
Control Systems
(cont'd)
OPERATION/SERVICE SECTION (cont'd)