| Options and Accessories Burners :
Propane firing - primary fuel - a
propane line burner is furnished with this option.
Propane firing - standby fuel - a three-way hand
valve is factory mounted. The pilot, however, stays on natural gas. This option
is not designed for use with mixed propane-air gas with properties similar to natural
gas. A standard burner will be furnished. Contact your Hastings sales
representative for special applications with two speed motors being used with
dual-fuel. Not available with selectra modulation systems or ETL units.
Gas Controls :
FM or IRI approved controls - additional gas
manifold controls are furnished to meet insurance authority requirements.
High gas pressure regulator - a high gas pressure
regulator is substituted for the standard regulator with inlet gas pressures over 1 PSIG
High or low gas pressure switch - manual reset type
with adjustable set point. Offered to meet special code requirements or where added
protection is desired. these gas pressure switches are part of the package furnished
with FM and IRI options.
Selectra modulation system - a solid state
electronic temperature control system is available to replace the standard self-contained
modulation valve on units 500 MBH or less. Both the Series 14 and Series 44 Selectra
systems are described below.
SELECTRA MODULATION SYSTEMS
SERIES 14
Selectra Series 14 electronic gas flame modulation
system features precise discharge air temperature control, decreasing variations or
temperature "swings"
All components are pre-calibrated - not requiring matching sets.
Temperature selector is mounted in any convenient location or the
dial can be incorporated in the remote control panel. Discharge air temperature can be
quickly and easily reset to meet changing requirements.
Thermistor in the discharge air monitor continuously senses outlet
air temperature and transmits an instantaneous signal, through a solid state amplifier, to
the modulator/regulator gas valve.
Immediately responding to the signal from the sensor, the
modulator/regulator valve changes gas pressure to control burner input and maintain
discharge air temperature at a constant level.
Options include -
Over-riding room thermostat - two position control
of space temperature.
Indoor-outdoor reset - raises discharge air
temperature one degree for every eight degree drop in outdoor temperature.
SERIES 44
The Selecta Series 44 system converts a single purpose make-up air
unit into one with dual operating characteristics , heating the ventilating air while
controlling the space temperature.
Series 44 features electronic modulating space
temperature sensing and control while, at the same time, preventing objectionable
discharge air temperature extremes.
The basic system includes a solid state amplifier/control center, a
discharge air monitor with high and low temperature thermistors, a modulator/regulator
valve, and a space temperature sensor with integral temperature selector.
As an alternative, a selectrastat and thermistor sensing remote
space temperature is also available. |
