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MYORK <br /> Page: 12 Guide Specification for <br /> Prestige <br /> A. Unit shall be complete with self-contained low-voltage control circuit protected by a resettable circuit breaker on the 24-volt <br /> transformer side. <br /> B. Unit shall incorporate a lockout circuit which provides reset capability at the space thermostat or base unit should any of the <br /> following standard safety devices trip and shut off compressor: <br /> C. Loss-of-charge/Low-pressureswitch. <br /> D. High-pressure switch. <br /> E. Freeze-protection thermostat, evaporator coil. If any of the above safety devices trip,an LED(light-emitting diode)indicator <br /> shall flash a diagnostic code that indicates which safety switch has tripped. <br /> F. Unit shall incorporate"AUTO RESET'compressor over temperature, over current protection. <br /> G. Unit shall operate with conventional thermostat designs and have a low voltage terminal strip for easy hook-up. <br /> H. Unit control board shall have on-board diagnostics and fault code display. <br /> I. Standard controls shall include anti-short cycle and low voltage protection,and permit cooling operation down to 0 OF. <br /> J. Control board shall monitor each refrigerant safety switch independently. <br /> K. Control board shall retain last 5 fault codes in non-volatile memory,which will not be lost in the event of a power loss. <br /> 23 09 23. 13.13 RTU Open-multi-protocol, direct digital controller <br /> 1. Shall be ASHRAE 62-2001 compliant. <br /> 2. Shall include built-in protocol for BACNET, Modbus,and Johnson N2. <br /> 3. Shall allow access of up to 62 network variables(SNVT). Shall be compatible with all open controllers <br /> 4. Baud rate Controller shall be selectable using a dipswitch. <br /> 5. Shall have an LED display independently showing the status of serial communication,running, errors, power, all digital <br /> outputs,and all analog inputs. <br /> 6. Shall accept the following inputs:space temperature, setpoint adjustment,outdoor air temperature, indoor air quality, <br /> outdoor air quality,compressor lock-out,fire shutdown,enthalpy switch, and fan status/filter status/humidity/remote <br /> occupancy. <br /> 7. Software upgrades will be accomplished by either local or remote download. No software upgrades through chip <br /> replacements are allowed. <br /> 23 09 33 Electric and Electronic Control System for HVAC <br /> 23 09 33. 13 Decentralized, Rooftop Units <br /> 23 09 33. 13.A General <br /> 1. Shall be complete with self-contained low-voltage control circuit protected by a resettable circuit breaker on the 24-v <br /> transformer side.Transformer shall have 75VA capability. <br /> 2. Shall utilize color-coded wiring. <br /> 3. Shall include a central control terminal board to conveniently and safely provide connection points for vital control <br /> functions such as:smoke detectors, phase monitor,gas controller,economizer,thermostat, DDC control options,and <br /> low and high pressure switches. <br /> 4. The heat exchanger shall be controlled by an integrated gas controller(IGC)microprocessor. See heat exchanger <br /> section of this specification. <br /> 23 09 33. 23.13 Safeties <br /> 1. Compressor over-temperature,over-current. High internal pressure differential. <br /> 2. Low-pressure switch. <br /> a. Units with 2 compressors shall have different sized connectors for the circuit 1 and circuit 2 low and high pressure <br /> switches.They shall physically prevent the cross-wiring of the safety switches between circuits 1 and 2. <br /> b. Low pressure switch shall use different color wire than the high pressure switch.The purpose is to assist the <br /> installer and service technician to correctly wire and or troubleshoot the rooftop unit. <br /> 3. High pressure switch. <br /> a. Units with 2 compressors shall have different sized connectors for the circuit 1 and circuit 2 low and high pressure <br /> switches.They shall physically prevent the cross-wiring of the safety switches between circuits 1 and 2. <br />