TC02 Curtain heater controller

Transcription

1 B U I L D I N G C O N F I D E N C E TC02 Curtain heater controller (Previously known as the mini-fcu) Operations & Maintenance manual TBControls 2011

2 CTENTS 1....DOCUMENT MANAGEMENT Change Control Document Review Document Status Document Ownership TC02 CTROLLER Design Features Connection terminals Disposal Engineering Supply cables Mounting the unit (if supplied without fan deck) WALL CTROL PLATE UNIT TC02 Connections MASTER / SLAVE Phased Start Sequence Controller Start sequence Error Messages Master Slave Messages LCD Modes LCD Set up Mode Engineering Mode User Mode Final checks before Power UP CTROL OPERATI SEQUENCES Sequence Sequence Sequence Sequence Graph settings Graph settings TC02 DIP-SWITCH SETTINGS OUTSIDE AIR TEMPERATURE SENSOR Fitting the sensor MODBUS PROTOCOL AND UNIT DATA FAULT FINDING Doc: TC02 O&M Page 2 of 20 Status: Final Issue: 11 TB Controls 2011

3 1. Document Management 1.1. Change Control Ver.No. Date of Status Changes Description/Comment Issue 1 8 Sept 04 Final All sections First Issue 2 13 Oct 04 Final Changes relating to additional air sensors 3 15 Oct 04 Final All sections Typographical amendments Increased index references 4 16 Nov 04 Final Section 7 added Outside sensor fitting 5 20 Nov 06 Final Name change & Various Mini-FCU changed to TC02 updates 6 7 Feb 06 Final Section 8 (fault finding) Updates from Diffusion added and various minor text changes 7 24 May 07 Final New mode to allow user Requested by Diffusion, interface to be locked TC02 firmware V July 08 Final MODBUS BMS interface TC02 firmware V4.00 details. L comms error for slave device added. Return air sensor now NOT required on slave units if fitted to master Sep. 09 Final L wire colour change to Requested by Diffusion match Diffusion drawings, terminals 11 and 13 (black and white) Apr. 10 Final Reverse sense option for return air sensor. Disable or Requested by Diffusion for New Look (firmware V4.10) setback heating when sensor is below a set-point Apr. 11 Final Set-point limits extended, DIP 5 for New Look settings 1.2. Document Review Reviewer. Rob Boardley Kevin Byrne Remit Technical Accuracy Presentation Requested by Diffusion for New Look (firmware V4.12) 1.3. Document Status FINAL 1.4. Document Ownership Rob Boardley Design & Development Doc: TC02 O&M Page 3 of 20 Status: Final Issue: 11 TB Controls 2011

4 2. TC02 controller 2.1. Design Figure 2- TC02 Controller Figure 1 - LCD The TB Controls TC02 controller is designed to be a cost effective multi-purpose digital control unit fulfilling the requirements for over-door curtain heaters and powerful fan coil units such as the Ambassador. It will control both electric and water fed units (air and water side types) or a combination of both. The control system consists of a control board of 140 mm long by 70 mm wide by 35 mm deep, mounted in the FCU and user display board of approximately 105 mm long by 60 mm wide. It is supplied on a standard 146 mm long by 81 mm wide electrical faceplate. The user display board has an alphanumeric LCD display. It is connected to the controller with a twin twisted pair cable Features The curtain heater controller unit has the following features Powered from volts AC or DC. Four fan speed settings with silent fan speed switching. Controlled by four snubberless triacs with heat sinks for increased current handling. Direct PID control of valve actuators for water fed systems. PID control of electric heating elements, with an external solid-state relay. Selectable off-coil setpoint from the values of up to 70 C. Master/slave control of fan speeds achieved with twin twisted pair between controllers. High precision digital temperature sensors, no cable length restrictions and calibration unnecessary. ELV Stat input to reduce or turn off heating when room temperature setpoint exceeded in curtain heater systems. On/off input for time clock or BMS control. BMS control of fan speeds. On/off input for occupancy sensor control. Settable run on time, default 15 minutes. Fault indication input for overheat trip display. Fault indicator output for BMS or panel display. Doc: TC02 O&M Page 4 of 20

5 Summer/Winter setting. Return air temperature measurement in place of room stat for greater flexibility Outside air temperature for fully automatic control. RS485 network communications, MODBUS open protocol. Full BMS monitoring and control. Additional features (for room FCU control available, not supplied with curtain heater controller) Silent PID control of two 24VAC heating and cooling actuators, or dampers, controlled by four snubberless triacs. Selectable room temperature setpoint from values of 17, 19, 21, 23 and 25 C. Lamp output for over-door welcome or security. The two spare triac outputs in an airside system can be used to drive 230 VAC lamps as in the Ambassador unit. On board real time clock for timed operation and event log time stamping. Log of the last 500 system events. Fan speed monitoring input to detect fan motor failure. DPS filter dirty input. RS485 network communications. LCD user display features for curtain heater Simple twin twisted pair connection to controller unit. 2 line 16-character LCD backlit display. Three buttons for control, mode, plus and minus buttons. Four fan speeds and off. Summer Winter or Automatic mode. Display of off coil temperature. Engineering settings such as sensor offset and setpoint step Connection terminals To avoid incorrect wiring, terminals that can be connected to AC 230 V (Fan speed and Lighting) are physically separate from the other terminals Disposal The controller contains electrical and electronic components and must not be disposed of as domestic waste. Current local legislation must be observed. Doc: TC02 O&M Page 5 of 20

6 2.5. Engineering Supply cables The TC02 controller requires a 12 to 24 VAC supply. The valve actuators may be rated between 24 VAC and 230 VAC. The controller does not supply actuators. Sizing and fuse protection of 230 VAC supply cables depends on the total load and on local regulations Mounting the unit (if supplied without fan deck) The controllers may be mounted in any orientation using metal Stand-offs, to suit the four fixing holes, the minimum stand-off height is 5mm, 3 mm fixing screws are recommended. Push over type plastic stand-offs may be used if it eases production. The following points should be noted; The controller should be freely accessible after mounting. Adequate air circulation to dissipate heat generated during operation. Easy access for service personnel. Local installation regulations must be observed. 3. Wall control plate unit The control plate for the TC02 is a second fix item. The following points should be noted; back box to receive the plate must be a double unit and a minimum of 47 mm deep Do not fix when plaster is wet Use connectors supplied to terminate the unit Follow the connection instructions with care Use sleeving on the drain wire Use shrink-wrap on the cable end to insulate foil Doc: TC02 O&M Page 6 of 20

7 3.1. TC02 Connections Connecting the field devices BMS / Time switch input ground ref. Return air sensor (data) Sensor ground ref. Overheat fault input ground ref. Occupancy PIR sensor or BMS summer/winter input ground ref VAC fan control Fan speed common output Fan speed 4 tap Fan speed 3 tap Fan speed 2 tap Fan speed 1 tap BMS 0-10v fan speed input BMS 0-10v ground ref. Occupancy PIR +12v feed L data loop for LCDs and slave TC02s L +12v output (red wire) L L1 data (white wire) L L2 data (green wire) L 0v ground (black wire) L earth (shield) Outside air sensor (data) ground ref. Heating SSR +ve Heating SSR output -ve Fault output ground ref. Fault output (switch to gnd) Off coil sensor (data) Sensor ground ref Earth 24VAC power 24VAC common (0v) 24VAC feed MODBUS RS485 network RS485 red wire (A) RS485 black wire (B) RS485 shield in RS485 shield out RS485 jumper on shield out Actuator drive open 24VAC feed Actuator drive closed Water control option DIP switch 4 = Caution There is no protection against accidental connection of 230 VAC to 24 VAC and data connections. Care must be taken to ensure connections for 230 VAC are made correctly and in accordance with local regulations Doc: TC02 O&M Page 7 of 20

8 4. Master / Slave Where several controllers are operating in the same space, they must be synchronized via the Master / Slave interface. Up to 8 slaves may be used (further options available) The operating parameters are passed via the data bus (L) Up to 8 control plates may be used. Single Belden 8723 cable connects slaves and control plates To set the unit to slave mode; Switch Dipswitch 8 to Master Unit will require Dipswitches 9 and 10 switched to and 8 to OFF Dip Switch 9 and 10 are the Terminating resistors for the L network on the Belden 8723 cable The Slave Address on the L is set using Dip switches 1, 2, and 3 giving 8 combinations addresses 0 to 7. The switches are set using Binary, (see notes on setting switches). Each slave unit in a group must have a different address. The Slave will follow all settings of the Master Each slave will report its faults to the Control Plate. Any unit may be set to a Master to suit site conditions; this must be the only Master unit of the group. Return air and Off coil temperature sensors are local to each unit Outside air temperature sensor is connected to the Master this input controls all slave units. BMS time switch control signal must be wired to the Master this input controls all slave units Phased Start Sequence The TC02 is designed for soft start, this avoids large numbers of fan decks switching on simultaneously causing electrical overload or tripping of circuit breakers due to very large starting currents, each unit has a delay of x ms. on power up. The phased start is set using the Dipswitches 1 to 7. The switches are set using Binary, (see notes on setting switches) 4.2. Controller Start sequence The TC02 has a green LED on board. This LED will flash three times on power up and afterwards will flash for 20mS every second. Three flashes, flash, flash, flash, indicates the unit has self tested and is OK. Regular flashing indicates unit is running OK Doc: TC02 O&M Page 8 of 20

9 4.3. Error Messages Master There are a number of possible error or operation messages; these will be displayed on the LCD screen. BMS or Time switch control when connected to the controller it will signal the controller to turn off. The controller will shut down the heating then work through the fan run on period, and then stop. The display will read; BMS/Time Switch Unit OFF Overheat Stat A temperature fault will be displayed when the cut out switch signals the controller. The display will read; Over Temperature Trip Occupancy sensing enables the controller for a predetermined period for example 10 minutes; if no further signal is received in this period then the unit will shut down and await a further occupancy signal. The display will read; Unoccupied Unit OFF Where the Off Coil Temperature sensor fails the heating will be turned off. The display will read; Off Coil Sensor Fault Where the Return Air Temperature sensor fails the heating will still be functional. The display will read; Return Air Sensor Fault Where the Outside Air Temperature sensor fails the display will read; Outside Air Sensor Fault Slave Messages Slave unit error messages will be displayed on the LCD unit with the Slave unit number. BMS or Time Switch: BMS/Time Switch...Slave X OFF Overheat stat: Over Temperature...Trip Slave X Occupancy sensor: Unoccupied...Slave X OFF Off Coil Sensor fault: Off Coil Sensor... Fault Slave X Return Air Sensor fault: Ret Air Sensor... Fault Slave X Slave comms connection fault: Slave X Comms Fault 4.4. LCD Modes There are three modes in the LCD display unit these are outlined below LCD Set up Mode To enter set up mode press and hold all three buttons for more than ten seconds, the unit will display LCD set up mode there are two options; module address x and backlight x The module address is the unique identity given to the unit to enable the Master unit to determine with which unit data is exchanged. Doc: TC02 O&M Page 9 of 20

10 To change address use outer buttons to increase or decrease the address number, a maximum of 8 can be set in one group. The LCD Backlight is the illumination property of the display; this allows the display to be read in poor light conditions. To alter the Back light on period use the outer buttons, the period can be from 1 to 25 seconds on or off Engineering Mode To enter engineering mode press and hold + and - buttons for more than ten seconds. The mode label will appear with stars *mode*. Pressing the mode button cycles through the readings and settings shown in quotes below. Some settings are displayed or omitted according to which sensors are fitted. Setpoints and outside temperature OS xx C RS xx C RT xx C OT xx C. Where OS is Off coil Setpoint, RS is Return air Setpoint, RT is Return air Temperature, OT is Outside Temperature. This temperature display will remain until the mode button is pressed, or the - button is pressed, in which case the Temperature and duty cycle are displayed. Pressing the mode button from this display will return to original display. Summer Off Coil Setpoint is displayed as Summer OC xx C. Range 10 to 70 C. Default 18 C Winter Off Coil Setpoint is displayed as Winter OC xx C. Range 10 to 70 C. Default 40 C Summer Return Air Setpoint / Trip is displayed as Summer Ret xx C Range -40 to 40 C. Default 16 C. When the temperature reaches this value the heater turns off or is setback by the Return Air Setback value. A negative value reverses the action, eg -10 would turn off or setback the heating at +10 C or below. The minus is ignored for calculations. In New Look mode (DIP 5 on) default is 18 C. Winter Return Air Setpoint / Trip is displayed as Winter Ret xx C Range -40 to 40 C. Default 25 C. When the temperature reaches this value the heater turns off or is setback by the Return Air Setback value. A negative value reverses the action, eg -10 would turn off or setback the heating at +10 C or below. The minus is ignored for calculations. In New Look mode (DIP 5 on) default is 18 C. Summer Outside Air Setpoint is displayed as Summer Out xx C Range -40 to 40 C. Default 20 C. In New Look mode (DIP 5 on) default is 10 C. Winter Outside Air Setpoint is displayed as Winter Out xx C Range -40 to 40 C. Default 15 C. In New Look mode (DIP 5 on) default is 0 C. Stat Offset or Return Air setback is the temperature setting in degrees, which the controller will use to adjust the output when it receives a signal from the Thermostat (Stat). Or return air sensor. Ret Setback xx C change steps using the +/- buttons. 0 C to 30 C. 0 C is off. Doc: TC02 O&M Page 10 of 20

11 Occupancy is detected by the occupancy sensor, this signal will be used by the controller to enable the fan and controls, the period for which it will work after detecting an occupant is set using the Occupancy Timer; Occupncy Tmr xxm change steps using the +/- buttons. 5 to 60 minutes in 5-minute steps. PIR Contact normally open or normally closed setting facility PIR Contact NC or NO Default N/O, closing to indicate occupancy Fan Run On timer is the time for which the controller will allow the fan to run after the unit has been switched off; this allows dissipation of residual heat on the heat exchanger. Fan Runon xxm change steps using the +/- buttons. 0 to 15 minutes in 1-minute steps. (Default 3 minutes) BMS Contact, normally open or normally closed setting facility. BMS Contact NC or NO Default N/O, closing to disable unit. BMS Summer/Winter input, if enabled (ENA) the PIR contact input becomes a summer/winter mode switch the "BMS S/W ip ENA or DIS" Default DIS (disabled). The input is open for Summer mode and closed for Winter mode. BMS 0-10v fan input, if enabled (ENA) the fan speed is taken from a 0-10v signal on the fan speed analogue input (see 3.1). The fan speeds are set as follows Fan Off: 0 volts (0v-2v) Fan speed 1: 3 volts (2v-4v) Fan speed 2: 5 volts (4v-6v) Fan speed 3: 7 volts (6v-8v) Fan speed 4: 9 volts (8v-10v) P I D terms P Factor x change steps using the +/- buttons. Change the Proportional value as instructed by factory. (Default 75 for electric and 30 for water) I Factor x change steps using the +/- buttons. Change the Integral value as instructed by factory. (Default 9 for electric and 4 for water) D Factor x change steps using the +/- buttons. Change the Differential value to suit. (Default 10 for electric and 0 for water) PWM Period adjustment, PWM P fast or slow. Default slow seconds period. Actuator travel time, hot water valve actuator travel time in seconds (default 150) used when DIP switch 4 is on, water heating system. Lock the user interface, Lock UI YES or NO, once set to yes the user cannot change any settings and pressing the buttons has no effect. The display shows Off coil temperature ( C), heater duty (0-100%), fan speed (Off,1,2,3,4) and mode (Summer/Winter/Auto). The summer/winter setting and fan speed cannot be changed without entering engineer mode (see 4.4.6). Doc: TC02 O&M Page 11 of 20

12 Factory Reset returns controller to factory defaults pressing the + button will restore the factory default settings. Pressing the button restores the last power up settings. Displays *Factory Reset* Factory reset will invoke a system temperature sensor recount, and will alter the operating parameters accordingly, ie if an outside air sensor is fitted or omitted. Firmware Version, Firmware V4.13, This menu is only available on firmware V4.12 and above. Displays the TC02 software version number. MODBUS network address, MODBUS add:1, This menu appears only if the MODBUS protocol option has been purchased. Sets the MODBUS open protocol RS485 network address. This must be different for each unit on the network, range is 1 to 247. MODBUS network baud rate, MOD baud:19200, This menu is only available on firmware V4.13 and above. Sets the MODBUS open protocol RS485 network baud rate. Default is baud, available baud rates are 2400, 4800, 9600, 19200, 38400, 57600, Engineer mode exits automatically after 30 seconds of inactivity, ie no buttons pressed User Mode User display mode default display when powered up will be Fan Status, it will read Fan Off or Fan Speed x on the top line and Mode on the bottom. Change Fan speed using the +/- buttons. If the user interface has been disabled the display is different see Lock the user interface above. The options are four speeds and Off. The unit will not turn the fan off if the heating has been on, this allows for cooling of the element. Run on time may vary ask engineering for the set time (normally 3 minutes). The Summer / Winter mode is selected by pressing the Mode button; the unit will display the status of the Heater Summer or Winter. If an Outside temperature sensor is fitted then selection is not possible and the display will read Automatic The Duty Cycle display is selected by pressing the Mode button, the top line will display Tp xx C Dty xx% this gives shows the Temperature at the grill Tp and the energy use as a percentage of the total available from the heater. These values will change relative to the temperature and the performance of the heater. TP xx C Dty xx% Temperature and Power Duty cycle Final checks before Power UP Check all connections Fan Solid State Relay / Actuator Sensor / Sensors BMS signals where present Doc: TC02 O&M Page 12 of 20

13 Trip for overheat sensor Room stat where present Occupancy sensor where present / if not insert loop! LCD Plate if used Communications cable L Communications cable Loop Mains transformer DIP switch 4 for water heating actuator control OFF for electric heating DIP switch 8 OFF, 9 and 10 for a Master unit DIP switch 8, 9 and 10 OFF for a slave unit Setting the unit up with the network address and the Slave address is covered in the following sections 5. Control Operation sequences The unit may be fitted with up to three sensors combinations of which will result in varied operation sequences Sequence 1 Off coil sensor only fitted will result in the temperature of the air leaving the supply grill being controlled to the given set point for Summer or Winter modes Sequence 2 Off coil and Return Air sensors only fitted will result in the temperature of the air leaving the supply grill being controlled to the given set point for Summer or Winter modes, however when the return air temperature reaches the appropriate setpoint trip the Off coil temperature setpoint will be adjusted according to the setback parameter Sequence 3 Off coil, Return Air and Outside Air sensors fitted will result in the temperature of the air leaving the supply grill being controlled to the given set point, automatically controlled between the Summer and Winter setpoints, (see ,13) however when the return air temperature reaches the appropriate setpoint trip the Off coil temperature setpoint will be adjusted according to the setback parameter. The return air trip setpoint is varied between the Summer and Winter setpoints as shown in , Sequence 4 Off coil, Return Air and Outside Air sensors fitted will result in the temperature of the air leaving the supply grill being controlled to the given set point, automatically controlled between the Summer and Winter setpoints. Doc: TC02 O&M Page 13 of 20

14 temperature C Default Set-points Operations & Maintenance Manual Setpoints Outside temperature C off coil setpoint return air trip Graph settings summer winter off-coil return air outside Doc: TC02 O&M Page 14 of 20

15 temperature C Operations & Maintenance Manual New Look Mode Set-points (DIP 5 on) Setpoints Outside temperature C off coil setpoint return air trip Graph settings summer winter off-coil return air outside 10 0 Doc: TC02 O&M Page 15 of 20

16 6. TC02 dip-switch settings MINI-FCU Dipswitch setting Master Dipswitch setting Switch position Switch Number Switches 9 and 10 Master Setting both on The above shows a Master Controller setting with a network address of 8 Slave Dipswitch setting Switch position Switch 8 Slave Setting on Switch Number The above shows a Slave Controller setting with a network address of 4 Table of Switches 1 to 8 Sw1 = 1, Sw2 = 2, Sw3 = 4, Sw4 = 8, Sw5 = 16 Sw6 = 32, Sw7 = 64, Sw8 = 128. Using various combinations of switches to 'on' the requires address up to a decimal value of 255 may be set see next illustration Dipswitch Settings Doc: TC02 O&M Page 16 of 20

17 Dipswitch settings from 0 to 17 D 8 H 8 Each switch has a Decimal and a Hexadecimal value. These values are shown as (D xx.) and (H xx) For example Number 4 switch has a value of 8 in decimal. Therefore Unit address 8 would be set as shown D 0 H 0 D 2 H 1 D 2 H 2 D 3 H 3 D 4 H 4 D 5 H 5 D 6 H 6 D 7 H 7 D 8 H 8 D 9 H 9 D 10 H A D 11 H B D 12 H C D 13 H D D 14 H E D 15 H F D 16 H 10 D 17 H 11 Doc: TC02 O&M Page 17 of 20

18 7. Outside air temperature sensor 7.1. Fitting the sensor For best results locate the sensor on the north side of the structure high under an eave. This prevents incorrect readings due to direct sunlight and damage from the elements. Mount vertically with the open end of the tube facing down to prevent the accumulation of dirt or water. North Installation example Doc: TC02 O&M Page 18 of 20

19 8. MODBUS protocol and unit data The hardware interface is half duplex RS485 (single twisted pair) and we normally use a ¼ unit load driver chip with +/-60 volt line protection (LT1785CN8). There are four screw terminal connections on the board these are RS485 B, RS485 A, Shield In, and Shield Out. Either or both Shield In and Shield Out can be connected to local ground via a jumper link. Normally only the Shield Out is linked to local ground. The open protocol is MODBUS RTU at baud (default), no parity, 8 data bits, and 1 stop bit. Each unit has a network address ID from 1 to 247 (8bit) settable from the LCD interface. The following MODBUS function codes are implemented Read Holding Registers (3) Write Single Register (6) The following data is available as 16bit signed integers Tag no. 0. Off coil temperature: in ¼ ºC 1. Return air temperature: in ¼ ºC (if fitted) 2. Outside air temperature: in ¼ ºC (if fitted) 3. Electric heater element duty: in % or hot water valve position in % open (0-100) 4. Fan speed: 0-4 (0=Off, 4=Maximum) (R/W) 5. Summer/Winter mode: 0=Summer, 1=Winter (R/W), 2=automatic (Read only) 6. Summer Off Coil Set-point: range 10 to 40ºC. Default 18ºC (R/W) 7. Winter Off Coil Set-point: range 40 to 70ºC. Default 40ºC (R/W) 8. Summer Return Air Set-point/Trip: range 10 to 40ºC. Default 16ºC (R/W) 9. Winter Return Air Set-point/Trip: range 10 to 40ºC. Default 25ºC (R/W) 10. Summer Outside Air Set-point: range 5 to 40ºC. Default 20ºC (R/W) 11. Winter Outside Air Set-point: range 5 to 40ºC. Default 15ºC (R/W) 12. Stat Offset or Return Air setback: 0ºC to 30ºC. 0ºC is off (R/W) 13. Occupancy Timer: time to keep the unit running after a occupancy signal is detected, 5 to 60 minutes in 1-minute steps (R/W) 14. Fan Run On time: 0 to 15 minutes in 1-minute steps (Default 3 minutes) (R/W) Error/Status bits readable from the master unit (15 master and slave units 0-7) Bit 0: BMS/Time Switch input active, Unit OFF (Remote disable) Bit 1: Over Temperature Trip Bit 2: Off Coil Sensor Fault Bit 3: Unoccupied Unit OFF (PIR sensor inactive for Occupancy timer period) Bit 4: Return Air Sensor Fault Bit 5: Outside Air Sensor Fault (master only, tag 15 only) Bit 6: Return air sensor setback active or Stat input trip Bit 7: spare Bit 8: Slave comms fault (16-23 only, occurs only when a slave has been connected) Bit 9: Slave connected (16-23 only) A master unit uses bits 8 and 9 in tag registers to indicate if a salve is connected or has become disconnected. Slave units can also be addresses on the MODBUS network with tag registers 0-15 available as read only data and tag 15 having bits 0-4 and 6 available. Tag registers marked (R/W) are Read and Write. A temperature value of 396, equivalent to 99ºC indicates a sensor not fitted or sensor fault, the appropriate bit will also bet set in the status register (tags 15-23) if this is a fault condition. Doc: TC02 O&M Page 19 of 20

20 9. Fault finding Fault Indication: module add 0 Check: The LCD has power but no data comms. Check wiring between LCD wall plate and unit mounted control board. Refer to wiring diagrams. Correct cabling has been used Beldon No LCD plate Wiring between LCD wall plate and unit mounted control board. Refer to wiring diagrams. Check main power supply into unit. Check transformer fuse (2A) on 24VAC supply. Check controller has 24VAC supply and 12VDC from controller. Check remote LCD wall plate has been earthed. Sensors Overheat Cut-out BMS Connections PIR Contact Slave X Comms Fault MODBUS network Check unit mounted control board, also making sure colours are correct to wiring diagram. Check fans are running. Check unit air inlet & discharge are not blocked. Should remote LCD plate read BMS/Time switch unit off, this may either be the main BMS system holding the units off or the N/O or N/C may need to be altered. The contacts can be altered by accessing the engineering mode. Should units be master/slaved it will also inform you of this. Should the LCD plate read unoccupied unit off the PIR contact may need to be altered, which can be accessed in the engineering mode or the PIR sensor may not have been activated. Should the LCD plate read Slave X Comms Fault The Belden cable between master and slave units has become damaged, disconnected or shorted. Check polarity of red and black wires at BMS connection, they may need to be reversed for correct operation. Make sure all network cables lengths have the shield wire connected to local earth at one end (jumper link on TC02). An unconnected shielded cable is worse than an unshielded cable! Check network address with BMS system. Each TC02 controller that is connected to the network must have a different MODBUS address (default is 1). Check baud rate, changeable from firmware V4.13 and above. Doc: TC02 O&M Page 20 of 20