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7. Shall ha ve an LED display independently showing the status of serial communication, running, errors, power,
all digital outputs, and all analog inputs.
8. Shall accept the following inputs: Space temperature, Set point adjustment, Outdoor Air temperature, indoor
Air quality, outdoor air quality, c ompressor lock--out, fire shutdown, enthalpy switch, and fan status/filter
status/ humidity/ rem ote occupancy.
9. Shall provide the following outputs: Economizer, fan, cooling stage 1, cooling stage 2, heat stage 1, hea t stage
2, heat stage 3/ exhaust/ reversing valve.
10. Shall have built--in surge protection circuitry t hrough solid state polyswitches. Polyswitches shall be used on
incoming power and network connections. Polyswitches will return to normal when the “trip” condition
clears.
11. Shall have a battery back--up capable of a minimum of 10,000 hours of data and time clock retention during
power outages.
12. Shall ha ve built--in support for Bryant service tool.
13. Shall include an EIA--485 protocol communication port, an access port for connection of either a computer or
a Bryant service tool, an EIA--485 port for network communication to intelligent space sensors and displays,
and a port to connect an optional LonWorks communications card.
14. Software upgrades will be accomplished by either local or remote download. No software upgrades through
chip replacements are allowed.
23 09 33 Electric and Electronic Control System for HVAC
23 09 33.13 Decentralized, Rooftop Units:
23 09 33.13.A. General:
1. Shall be complete with self--contained low--voltage control circ uit protected by a fuse on the 24--v transformer
side (04--07 units have a resettable c ircuit breaker).
2. Shall utilize color--coded wiring.
3. Unit shall be include self--contained low--voltage control circuit protected by a fuse on the 24--v transformer
side with a resettable circuit breaker.
4. The heat exchanger shall be controlled by an integrated gas controller (IGC) microprocessor. See heat ex-
changer section of this specification.
5. Unit shall include a minimum of one 8--pin screw terminal connection board for connection of control wiring.
23 09 33.23.B, Safeties:
1. Compressor over--tempe rature, over current.
2. Low--pressure switch.
a. Units with 2 compressors shall have different siz ed connectors for the circuit 1 and circuit 2 Low and High
Pressure switches. They shall physically prevent the c ross--wiring of t he safety switc hes between circ uits 1
and 2.
b. Low pressure switch shall use different color wire than the high pressure switch. The purpose is to assist
the installer and service person to correctly wire and or troubleshoot the rooftop unit.
3. High--pressure switch.
a. Units with 2 compressors shall have different siz ed connectors for the circuit 1 and circuit 2 Low and High
Pressure switches. They shall physically prevent the c ross--wiring of t he safety switc hes between circ uits 1
and 2.
b. High pressure switch shall use different color wire than the low pressure switch. The purpose is to assist the
installer and service person to correctly wire a nd or troubleshoot the rooftop uni t.
4. Automatic reset, motor thermal overload protector.
5. N/A
23 09 93 Sequence of Operations for HVAC Controls
23 09 93.13 Decentralized, Rooftop Units:
23 09 93.13 INSERT SEQUENCE OF OPERATION
23 40 13 Panel Air Filters
23 40 13.13 Decentralized, Rooftop Units:
23 40 13.13.A. Standard filter section shall
1. Shall consist of factory--installed, low velocity, throwaway 2--in. thick fiberglass filters of commercially avail-
able sizes.
2. Unit shall use only one filter size. Multiple sizes are not acceptable.
3. Filter face velocity shall not exceed 365 fpm at nominal airflows.
558J