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T7350
Commercial Programmable Thermostat
SYSTEM ENGINEERING
Contents
Introduction .................................................................................................................................. 2
Device Description .............................................................................................. 2
Control Application .............................................................................................. 2
Network Control Provided ...........................
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT INTRODUCTION Device Description Control Application ® The T7350H is a LONMARK certified thermostat that provides The T7350H programmable communicating Thermostat ® networking capability in a LONWORKS system using a controls commercial single zone heating, ventilating and air transformer-coupled Free Topology Transceiver (FTT). See conditioning (HVAC) equipment through staged and Fig. 1. modulating outputs. The T7350H consists of a two piece assembly w
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT Network Control Provided Products Covered The T7350H communicates with other network devices, or This System Engineering manual describes how to apply the nodes, for sharing data such as local inputs. Through the T7350H Communicating Thermostat and related accessories network, a Command Display (S7760) is used to view or to typical applications. Devices include: modify T7350H operational modes including: T7350H Commercial Communicating Thermostat. W
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT LONSPEC) that writes the binding information into the Applicable Literature EEPROM memory of all the neurons involved. The binding The following list of documents contains general information information is saved in the network image of each neuron. related to the T7350H Communicating Commercial Thermostats. ® Building ManagerA LONMARK certified device that can be used to monitor and control HVAC equipment and other Table 3. Applicable Literature
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT Network VariablesA class of variables defined in Neuron C RIOExcel 10 Remote Input/Output device. ® that allows communication over the LONWORKS network to other nodes on the network. An output network variable in one RTCReal Time Clock. node can be bound to a corresponding input network variable(s) in other node(s). Changing the value of the output ScheduleThe structure that defines the occupancy states network variable in one node causes the new v
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT Mounting Means: Communicating Model T7350H: ® Mounts on subbase. Connection Terminals for the LONWORKS Bus. Subbase Mounts On: Network jack for quick access by personal computer based Wall: Using two 5/8 in. long #6-32 screws (included). tools. Outlet Box: Using sheet metal screws. Communications service-pin pushbutton to simplify startup. ® LONMARK Functional Profile: 8500_20 Space Comfort Throttling Range for Modulating Outputs: Controller. ® Automati
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT Communications 2-3/16 (56) ® The T7350H provides networking capability in a LONWORKS 1-9/16 6-3/4 (171) system using a Free Topology Transceiver (FTT) transformer- (40) coupled communications port running at 78 kilobits per second (kbs). The transformer-coupled communications interface offers a much higher degree of common-mode noise ® rejection while ensuring dc isolation. LONWORKS FTT 4-1/2 networks are very flexible and convenient to install and
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT ® LONMARK Functional Profile Hardware Output Hardware Output Node SCC-Rooftop Object Object Number 8504. nviRequest nvoStatus nviSpaceTemp nvoSpaceTemp Mandatory nv1 nv1 nv2 Mandatory nv26 SNVT_obj_request SNVT_ obj_status SNVT_temp_p SNVT_ temp_p Network Network nvoUnitStatus Variables Variables nv27 SNVT_hvac_status nviTimeSet nvoFileStat nv3 nv6 SNVT_ time_stamp SNVT_file_status nviSetpoint nvoEffectSetpt nv2 nv28 Optional SNVT_ temp_p SNVT_temp_p nv
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT the user is not prevented from making local schedule NETWORK CONFIGURATIONS changes at the recipient thermostat. Local schedule changes (at a recipient device) have no effect on the The T7350H can be configured to perform a variety of scheduling commands received from the master device. activities in which data is sent to and/or received from other When a T7350H is designated as a master schedule ® nodes on the LONWORKS network. Information that ca
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT value will be used in the T7350H as the primary controlled Occupancy Bypass: variable. The local space temperature sensor of the Any internal or external scheduled unoccupied state in the T7350H is ignored until the network sensor fails. T7350H is overridden by a network occupancy bypass command. Bypass is a method to command unoccupied Source Destination override over the network from another controller (typically a T7350H or XL10). The source co
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT Refer to the Light Commercial Building Solution System Step 2. Determine Required Network Devices Communication Guide form 71-3123 and the E-Bus Wiring A maximum of 60 nodes can communicate on a single Guidelines, form 74-2865 for a complete description of ® ® LONWORKS Bus segment. Each LONWORKS Bus device network topology rules. Prepare Wiring Diagrams, for wiring comprises one node. If more than 60 nodes are needed, a details. Plan to configure e
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT Cable Termination CAUTION The FTT network segment requires termination for proper data transmission performance. Use a 209541B Termination Electrical Shock or Equipment Damage Hazard. Module to connect two of the three termination module wires Can shock individuals or short equipment ® ® to the LONWORKS Bus terminals. Refer to LONWORKS Bus circuitry. Wiring Guidelines form 74-2865 for details. Disconnect power supply before installation. IMPORTANT Sin
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT OUTDOOR 4 AIR COMPRESSOR T7770 REMOTE SENSOR ECONOMIZER SENSOR CONTACTOR 2 DISCHARGE HEAT HEAT 9 8 7 6 5 4 3 2 1 AIR RELAY 3 RELAY 2 SENSOR SUBBASE T5 T6 T7 T4 T3 OS OS AS AS AUX W3/Y4 Y3 W2 Y2 EB EB HS HC HP M M X RH RC AUX W1 Y1 G COMPRESSOR CONTACTOR 3 ® LONWORKS 3 HEAT FAN HUMIDITY MOTION BUS RELAY 1 RELAY SENSOR SENSOR ® LONWORKS BUS COMPRESSOR CONTACTOR 1 L2 1 2 L1 (HOT) 1 POWER SUPPLY. PROVIDE DISCONNECT MEANS AND OVERLOAD PROTECTION AS REQUIRED
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT OUTDOOR MODULATING R AIR – COOL T7770 REMOTE SENSOR SENSOR + (4-20 mA) X MODULATING R DISCHARGE 9 8 7 6 5 4 3 2 1 – HEAT AIR + (4-20 mA) X SENSOR SUBBASE T5 T6 T7 T4 T3 OS OS AS AS AX AH AC AUX EB EB HS HC HP M M X RH RC AUX W1 Y1 G 2 ® LONWORKS FAN HEAT HUMIDITY MOTION BUS RELAY RELAY 1 SENSOR SENSOR ® LONWORKS BUS COMPRESSOR CONTACTOR 1 3 L2 1 ECONOMIZER L2 L1 1 (HOT) L1 (HOT) HEATING TRANSFORMER COOLING TRANSFORMER 1 POWER SUPPLY. PROVIDE DISCONNECT
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT General Considerations Table 8 lists wiring types, sizes and distances for the T7350 and Excel 10 products. The T7350 terminal strip accepts 18 through 22 AWG (0.82 to 0.34 sq. mm) wire. Table 8. Field Wiring Reference. Recommended Wire Specification or Honeywell Part Wire Function Size (Minimum) Requirement Number Distance (Maximum) Digital Outputs: 18 AWG (0.82 sq mm) Standard thermostat AK3726 1000 feet. W Y G AUX X five wire cable bundle. wire. Mo
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT Table 9. Honeywell Cable Details. Honeywell Part Number Size (AWG) Number of wires Jacket Plenum Rated Description AK3798 22 2 Yes No E-bus cable. AK3797 22 2 Yes Yes E-bus cable. AK3799 22 4 Yes Yes E-bus cable. AK4606ABE 22 2 Yes No Beige jacket. AK4628AWH 22 2 Yes Yes White jacket. AK3702x 18 2 No No AK3741A 18 2 Yes No AK3744C 18 2 Yes Yes Red jacket. AK3757C 18 2 Yes Yes White jacket. AK3703x 18 3 No No AK3724 18 3 Yes No Tan jacket. AK3746C 1
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT Step 5. Order Equipment After compiling a bill of materials through completion of the previous application steps, refer to Table 10, Ordering Information. Table 10. Ordering Information. Part Number Product Description Comments T7350H1009 Communicating Thermostat with three heating and Optional heat pump control. three cooling digital outputs. Isolated auxiliary digital output. T7350H1017 Communicating Thermostat with two modulating Isolated auxil
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT Step 7. Troubleshooting Table 11. Troubleshooting Information. Symptom Possible Cause Action Display will not Thermostat is not being powered. Check that X terminal is connected to the system transformer. come on. Check for 24 Vac between X and RH terminals. If missing 24 Vac: Check if circuit breaker is tripped; if so, reset circuit breaker. Check if system fuse is blown; if so, replace fuse. Check if the HVAC equipment power switch is in the Off p
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT Table 11. Troubleshooting Information. (Continued) Symptom Possible Cause Action Cooling will not No power to the thermostat. Check that X terminal is connected to the system transformer. come on. Check for 24 Vac between X and RH terminals. If missing 24 Vac: Check if circuit breaker is tripped; if so, reset circuit breaker. Check if system fuse is blown; if so, replace fuse. Check if the HVAC equipment power switch is in the Off position; if so,
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T7350 COMMERCIAL PROGRAMMABLE THERMOSTAT APPENDIX A - NETWORK TOOLS & WORKSTATIONS Table 12. T7350H Operational Support. Network Tools & Workstations Summary of T7350H Operational Support Device Configuration X X X View & Modify Weekly Schedule X X X X X View & Modify Holiday Schedule X X X X X Data Monitoring XXXX XX Command Outputs to Manual Value X X X X Override System Delays X X X X Room Temperature Calibration X X X Command Occupancy Override XXXX XX Command Fan Operation (On Auto) X X X
