48
7. Shall ha ve an LED display independently showing the status of serial communication, running, errors, power,
all digital outputs, and all anal og inputs.
8. Shall accept the following inputs: Space temperature, Set point adjustment, Outdoor Air temperature, indoor
Air quality, outdoor air quality, compressor 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, c ooling stage 2, heat stage 1, heat stage
2, heat stage 3/ exhaust/ reversing valve.
10. Shall have built--in surge protection circuitry through 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 e ither 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 Ele ctric and Ele ctronic Control System for HVAC
23 09 33.13 Decentralized, Rooftop Units:
23 09 33.13.A. General:
1. Shall be complete wit h self--contained low--voltage control circuit prote cted by a fuse on the 24--v transformer
side (04--07 unit s have a reset table circuit brea ker).
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 inte grated gas controller (IGC) microprocessor. See heat ex-
changer section of this specification.
5. Unit shall include a minimum of one 8--pin screw te rminal connection board for connection of control wiring.
23 09 33.23.B, Safeties:
1. Compressor over--temperature, over current.
2. Low--pressure switch.
a. Units with 2 compressors shall have different sized connectors for the circuit 1 and circuit 2 Low and High
Pressure switches. They shall physically prevent the c ross--wiring of the safety switc hes between circuits 1
and 2.
b. Low pressure switch shall use different color wire t han 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 sized connectors for the circuit 1 and circuit 2 Low and High
Pressure switches. They shall physically prevent the c ross--wiring of the safety switc hes between circuits 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 c orrectly wire and or troubleshoot the rooftop unit.
4. Automatic reset, motor thermal overload protector.
5. N/A
23 09 93 Sequence of O perations 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
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