Boiler Management System DISPLAY MODE Installation Operation & Troubleshooting Instructions FIELD ADJUSTMENT MODE Hold Key for Header Set Raise/Lower To Change HDR TEMP Display Header Temp., oF FIELD ADJ L.E.D. "On" Enables Field Adjustment AIR TEMP Display Outside Air Temp., oF SYS START TEMP % LOAD Display % Load & No. of Units Operating REF TEMP Select System Start Option Display/Change Outside Air Temp.
Telephone Support Direct to AERCO Technical Support (8 to 5 pm EST, Monday through Friday): 1-800-526-0288 The information contained in this installation, operation and maintenance manual is subject to change without notice from AERCO International, Inc. AERCO International, Inc. 159 Paris Avenue Northvale, NJ 07647-0128 www.aerco,com © AERCO International, Inc.
Table of Contents Page SECTION 1 ABOUT YOUR NEW BOILER MANAGEMENT SYSTEM (BMS) 1-1 SECTION 2 FEATURES OF THE BMS 2-1 SECTION 3 INSTALLING THE BMS 3-1 3.1 MOUNTING THE BMS 3.2 GENERAL WIRING 3.3 PULSE WIDTH MODULATION WIRING 3.3.1 PWM Wiring at BMS 3.3.2 PWM Wiring at Boilers 3.4 RS485 (MODBUS) WIRING 3.4.1 RS485 Wiring at BMS 3.4.2 RS485 Wiring at Boilers 3.5 SENSOR INSTALLATION AND WIRING 3.5.1 Header Sensor 3.5.2 Outside Air Sensor 3.6 INTERLOCK WIRING 3.6.1 Interlock 1 Wiring 3.6.
Table of Contents (Continued) 4.2.13 ON and OFF Keys 4.2.14 CONFIG SYS 4.3 FIELD ADJUST MODE FUNCTIONS 4.3.1 HDR TEMP 4.3.2 AIR TEMP 4.3.3 % LOAD 4.3.4 Setting the Internal Clock With the % LOAD Key 4.3.5 SYS START TEMP 4.3.6 REF TEMP 4.3.7 HDR TEMP LIMIT 4.3.8 FIELD ADJ 4.3.9 SET POINT 4.3.10 PROP BAND 4.3.11 OFFSET 4.3.12 Setting Up a Reset Schedule 4.3.13 Manual Set Back 4.3.14 RESET RATIO 4.3.15 ▲ and ▼ Arrow Keys 4.3.16 ON and OFF Keys 4.3.17 CONFIG SYS 4.4 SYSTEM CONFIGURATION MODE FUNCTIONS 4.4.
Table of Contents (Continued) SECTION 5 PROGRAMMING THE BMS MODE OF OPERATION 5.1 INDOOR/OUTDOOR RESET MODE 5.1.1 Selecting Indoor/Outdoor Reset Mode 5.1.2 Entering System Start Temperature 5.1.3 Determining the Reset Schedule 5.1.4 Entering the Building Reference Temperature 5.1.5 Entering the Reset Ratio 5.2 SETUP FOR REMOTE SETPOINT MODE 5.2.1 Entering Header Set and Boiler Operating Modes 5.2.2 Entering Remote Signal Type and Header Temperature Limits 5.3 SETUP FOR CONSTANT SETPOINT MODE 5.3.
List of Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Figure 9 Figure 10 Figure 11 Figure 12 Figure 13 Figure 14 Typical BMS Installation BMS Mounting Wire Routing Locations at the BMS PWM Communication Outputs at the BMS Pulse Width Modulation Connections at KC Series Boiler Boiler With Modular Control Box PWM & RS485 Connections at KC Series Boiler With C-More Control Box Pulse Width Modulation Connections at the Benchmark Boiler With Modular Control Box PWM & RS485 Conn
Section 1 ______________________________ About Your New Boiler Management System (BMS) SIMPLE INSTALLATION AND OPERATION Installation of the BMS is simple, and lowvoltage wiring is employed between the BMS panel and boiler modules. There are no complex design steps to be performed, since a keypad in conjunction with the LCD allows the operator to acquire, change, and program settings through easy-to-use labeled buttons.
Section 2 ______________________________ Features of the BMS____ SEQUENTIAL OR PARALLEL OPERATION Modules can be either sequenced on, or run in parallel, by selection from the front panel. In sequential mode, boilers are brought on one at a time, so turn-down ratio is 14 multiplied by the number of KC Series boilers, or 20 multiplied by the number of Benchmark boilers. This provides higher energy savings and seasonal efficiency.
CONTROL OF AUXILIARY EQUIPMENT Time Delay Between Boiler Starts: A fixed, 30-second time delay between boiler starts ensures smooth energy input without spikes in electrical, gas, or venting conditions. The auxiliary relay uses a dry set of contacts to operate auxiliary equipment. For example, when the boiler plant is at 100% load, these contacts close and can start an auxiliary boiler, or notify an energy management system of a full-load condition.
Section 3 ______________________________ Installing the BMS________ 3.2 GENERAL WIRING Shielded, twisted-pair cable should be used for sensor and communication wiring. This wiring should be 18 to 24 AWG. Examples of suitable sensor and communication wire are: Belden 9841, 8761, 3105A or equivalent. AC power wiring should be 16 to 18 AWG. A BMS wiring diagram is included in Appendix I.
Regardless of the type of control system used, the PWM wiring is connected to the BMS + and – terminals as shown in the respective illustrations. It is imperative that positive (+) and negative (-) polarity be observed when making these connections. All boilers follow the same control wiring scheme. WARNING! Turn off AC input power to the BMS to avoid electrical shock. 3.
3.5.1 Header Sensor The header sensor to be used with the BMS is a sensor that requires a well as shown in Figure 11. When installing the sensor, use a 1/2 inch NPT tapped coupling or a 4 x 4 x 1/2 Tee fitting. Use heat-conductive grease when installing to aid in its response. The sensor probe must be inserted at least 2 inches into the flow of water for proper response. The header sensor must be installed between 2 and 10 feet downstream of the LAST boiler in the plant’s supply water header.
3.6 INTERLOCK WIRING 3.7 1 System Start Relay The state of the System Start (SYS START) relay contacts are controlled by the value set for the SYS START TEMP function in the Field Adjust Mode (para. 4.3.5). The contacts are closed only when the outside air temperature is less than the System Start Temperature (SYS START TEMP) which is set in the Field Adjust Mode. The default for this temperature setting is 70°F.
3-5
Figure 2 BMS MOUNTING 3-6
Figure 3 RECOMMENDED WIRE ROUTING LOCATIONS AT THE BMS 3-7
Figure 4 PWM COMMUNICATION OUTPUTS AT THE BMS 3-8
Figure 5 PULSE WIDTH MODULATION CONNECTIONS AT KC SERIES BOILER WITH MODULAR CONTROL BOX 3-9
Remove sheet metal cover to access I/O Box OUTDOOR SENSOR IN SENSOR COMMON AUX SENSOR IN REMOTE INTL'K IN EXHAUST SWITCH IN DELAYED INTL'K IN NOT USED NOT USED NC COM NO + ANALOG IN+ B.M.S. (PWM) IN- NC COM NO RS-485 COMM.
Figure 7 PWM CONNECTIONS AT BENCHMARK BOILER WITH MODULAR CONTROL BOX 3-11
Open Door To Access I/O Box OUTDOOR SENSOR IN SENSOR COMMON AUX SENSOR IN REMOTE INTL'K IN EXHAUST SWITCH IN DELAYED INTL'K IN NOT USED NOT USED NC COM NO + ANALOG IN- NC COM NO + B.M.S. (PWM) IN - FAULT RELAY 120 VAC, 5A, RES AUX RELAY 120 VAC, 5A, RES NOT USED SHIELD + mA OUT RS-485 + G COMM.
Figure 9 BMS RS485 & RS232 CONNECTOR LOCATIONS 3-13
Figure 10 BMS RS485 & RS232 CONNECTOR PIN ASSIGNMENTS 3-14
1/2 “ NPT Figure 11 HEADER SENSOR INSTALLATION WITH WELL 3-15
Figure 12 OUTSIDE AIR SENSOR MOUNTING AND CONNECTIONS 3-16
Section 4 ______________________________ 4.1.1 Selecting and Viewing Functions As previously mentioned, the Normal mode, is a read-only mode which allows functions to be viewed, but not changed. However, functions associated with the keypad keys can also be viewed in the FIELD ADJ and CONFIG SYS modes, provided the appropriate mode key (FIELD ADJ or CONFIG SYS) is first selected. For example, pressing the HDR TEMP key displays the supply water temperature.
Figure 13 NORMAL & FIELD ADJUST MODE OVERLAY 4-2
Figure 14 SYSTEM CONFIGURATION MODE OVERLAY 4-3
NOTE Sample Normal Mode displays with their Factory Default values are provided in Appendix C. 4.2.6 HDR TEMP LIMIT Pressing and holding this key displays the header high limit temperature setting (°F) stored in memory. 4.2 NORMAL MODE DISPLAYS AND FUNCTIONS 4.2.7 FIELD ADJ Pressing and releasing this key places the BMS in the Field Adjust Mode and lights the FIELD ADJ key LED. When this key is pressed, the display will read FLD ADJUSTMENT MAKE SELECTION. Refer to paragraph 4.
NOTE When in the Field Adjust Mode, the HDR TEMP and AIR TEMP keys are used to set multiple functions required for Modbus Network operation. Refer to Modbus Communication Manual GF-114 for additional information on set-up and installation of Modbus (RS485) Networks. 4.2.12 ▲ and ▼ Arrow Keys The ▲ and ▼ arrow keys are not active in this mode, since no changes can be made to the displayed settings 4.2.13 ON and OFF Keys Pressing and releasing the ON or OFF key enables or disables the BMS.
4.3.4 Setting the Internal Clock With The % LOAD Key 7. Repeatedly pressing the HDR TEMP key allows the NETW BOILER ADDRESS to be set for each boiler being controlled on the Modbus Network. Pressing and releasing the % LOAD key changes the first line of the display to SET TIME CLOCK. The second line of the display will show: MONTH, DATE, YEAR, DAY, HOURS, or MINS.
LOAD) must be above 11%. Second the outdoor air temperature must be below the system start temperature. The system start relay contacts will open when the load percentage falls below 7%. 4.3.5 SYS START TEMP When in the Field Adjust Mode, the SYS START TEMP key has two functions. First, It lets you select the outdoor temperature at which the system starts. Second, it lets you select the system start option (TEMP ONLY or TEMP AND LOAD). 4.3.
4.3.8 FIELD ADJ The FIELD ADJ key LED should be lit to indicate that the BMS is already in the Field Adjust Mode. Pressing and releasing this key when already in the Field Adjust Mode will cause the BMS to exit the Field Adjust Mode and switch the BMS to the Normal (Read-Only) Mode. be controlled manually by connecting a switch across the SET BACK wiring terminals (see para. 3.8). If a manual offset is used, refer to paragraph 4.3.13 IMPORTANT Prior to setting up an automatic Reset Schedule (para. 4.3.
outdoor air temperature. For example, if the building reference temperature is set at 70°F, when outside air temperature drops to 69°F, and the reset ratio is 1.8, the water supply temperature will increase to 71.8°F. AERCO presets the Reset Ratio to 1.2°F/°F. See Appendix B for Reset Ratio Charts. 5. Press key a fifth time. OFFSET OFF TIME DAY 1 Æ 0: 0 is displayed prompting Hours to be entered for off time. Since the BMS uses a 24-hour clock format, set the Hours to 8 using the ▲ and ▼ arrow keys. 6.
4.4 SYSTEM CONFIGURATION MODE DISPLAYS AND FUNCTIONS Selecting INTERLOCK 2 causes the Fault Relay to close and generate an alarm only when Interlock 2 opens. However, if INTERLOCK 1 opens, a fault message will be generated but the Fault Relay will not be closed. The System Configuration Mode allows you to program and operate the BMS to effectively run and manage the performance of the boiler plant.
ENABLED or ALWAYS ENABLED is selected. AERCO recommends that the system be equipped with a flow switch that is interlocked to the BMS. This is especially important if ALWAYS ENABLED is selected and the BMS is controlling the pumps based on outside air temperature, or the BMS is interfaced with an energy management system that is controlling the pumps. If SWITCH INPUTS is selected, the BMS will automatically switch to Constant Setpoint mode if a sensor or remote input error occurs.
4.4.4 START LEVEL and STOP LEVEL Keys 4.4.5 BLR OP MODE This key is used to select the Boiler Operating Mode. It allows you to make choices concerning the effective and efficient way to fire the boilers based on the building load. The mode choices include: Parallel, Sequential, or Combination Mode. These keys allow you to set the energy levels (firing rate percentages) at which additional boilers are staged-in or stagedout of the system during Sequential or Combination mode operation.
As the load drops off, the firing rates decrease. When all boilers reach the stop level, the first boiler turned on will be shut off by the BMS and its load will be evenly distributed to the remaining firing boilers. This off-sequencing continues until only one boiler is left firing. The last boiler will turn off when its stop level is reached. 1. With the COMBINATION MODE selected, press the BLR OP MODE key.
specific installation. The factory defaults preset by AERCO work well for most applications. In instances when there is a large error between the setpoint and the actual supply water temperature, the BMS may appear to require PID tuning. However, It is best to observe BMS operation over a period of time prior to making any PID changes. Contact AERCO or an AERCO representative prior to making any PID setting changes. 4.4.7.2 INTGL RATE GAIN Integral gain responds to the setpoint error over a period of time.
4.4.8 AUX RELAY When in Combination Control Panel (CCP) mode, care must be taken to ensure that the AUX RELAY OPEN percentage is set so that the system does not oscillate turning boilers on and off. A maximum open percentage of 45% is recommended for Combination Control mode. If using the AUX contacts to fire an auxiliary boiler, the recommended open percentage is 70%. This key is used to display or change the firing rate at which the Auxiliary Relay opens and closes.
Section 5 ______________________________ Programming the BMS Mode of Operation__ 3. Press the HDR SET MODE key once. HEADER SET MODE is displayed with the present mode selection. 4. While observing the display, toggle the HDR SET MODE using the ▲ or ▼ key to IN/OUTDOOR RESET. 5. Press the CONFIG SYS key to exit the System Configuration mode. The key LED will go off. Prior to programming, the BMS must be mounted and all required wiring completed.
5.2.1 Entering Header Set Mode and Boiler Operating Mode These selections are made with the BMS in the System Configuration mode. Proceed as follows: 5.1.4 Entering the Building Reference Temperature To enter the Building Reference Temperature, perform the following steps: 1. Enter Field Adjust mode by pressing the FIELD ADJ key. Verify that the key LED illuminates. 1. Press the CONFIG SYS key to enter the System Configuration mode. The CONFIG SYS key LED will illuminate. 2. Press the REF TEMP key.
5. Press the BLR OP MODE key. BOILER OP MODE is displayed with the presently stored mode selection. NOTE Steps 5, 6 and 7 scale the 20 mA Remote Signal to the selected HDR HIGH LIMIT and HDR LOW LIMIT settings. 6. Select the PARALLEL, SEQUENTIAL or COMBINATION MODE using the ▲ or ▼ arrow key. 5. Select the desired header high temperature limit setting using the ▲ and ▼ arrow keys. The selected temperature will be equal to a 20 mA Remote Signal. 7.
5.4.2.2 Configuring the Temperature 5.4.1 C-More Control System PWM Setup For PWM communication, each boiler’s CMore Control System must have the Configuration Menu items properly set up as follows: Controller Once addressing has been completed, it is necessary to perform two more configuration steps to each boiler’s temperature controller. Each temperature controller must be in the Remote and Auto/Off (Manual) modes for proper communication and operation with the BMS. 1.
5.6 TESTING THE SYSTEM 10. Set the HEADER REF. TEMP (setpoint) to 220°F using the ▲ and ▼ arrow keys. The following procedure places a load on the system and will begin firing the boilers. At this point it is very important to make sure the system pumps are running. 11. Press the FIELD ADJ key. The LED will turn off. 12. Press the %LOAD key and monitor the display for the firing rate (PERCENT OF LOAD) and the number of boilers firing (Units).
Appendix A ____________________________ SPECIFICATIONS INPUTS POWER Input voltage 120 VAC, 60Hz, 1 phase, ± 10%, fused at 1 A OUTSIDE AIR SENSOR (NTC thermistor) Acceptable types AERCO GP-122662 (Sensor Only) or GM-122781 (Sensor & Mounting Plate) Range -60°F to +80°F Short sensor protection Invoked at +200°F HEADER SENSOR (NTC thermistor) Acceptable types AERCO 64038 (Sensor Only) or GM-122790 (Sensor and Thermowell) Range 40°F to +220°F Short sensor protection Invoked at +300°F INDOOR TEMP
Appendix A (cont.) ________________________ CURRENT LOOP Input resistance 250 Ohms Protection Isolated from AC line potential, fuse-protected at 62 mA, open loop detected at <1 mA Operational current range 4 mA to 20 mA SET BACK Input 12 VDC at 15 mA.
Appendix A (cont.) ________________________ BOILER DRIVE Drive Type (PWM) Signal (with 12 msec time base) Optically-isolated, pulse width modulated Valve drive 100% fire rate at 95% pulse width, 0% fire rate at 5% pulse width Current Loop Determination Optically isolated detection MEMORY Non-Volatile Memory EPROM storage of system input. Variables changed in Field Adjust or Configure System mode. EPROM storage of on/off state.
Appendix A (cont.) ________________________ DEFAULT VALUES System State Header Set Mode Indoor Air Input Boiler Op Mode Halted (stop mode) Indoor/Outdoor Reset Thermistor Sequential Start Level 45% Stop Level 18% Auxiliary Relay Open 45% Fire Rate Auxiliary Relay Close 100% and Off Header Temperature Bandwidth 70°F Integral Gain .15 repeats/min. Derivative Gain .
Appendix B _____________________________ Methods for Determining Reset Schedule and Indoor/Outdoor Reset Ratio Charts Using the Charts to Determine Reset Schedule for example, If Toutside varies from -10 to +95°F (105° range), and Each table in this appendix provides data for a specific building reference temperature. On the vertical axis of each table are degree day temperatures. These are the average lowest temperatures likely to be encountered.
Appendix B (cont.) _________________________ Header Temperature for a Building Reference Temperature of 50°F Air Temp (°F) 0.6 0.8 1.0 Reset Ratio 1.2 1.4 1.6 1.
Appendix B (cont.) _________________________ Header Temperature for a Building Reference Temperature of 65°F 0 Air Temp ( F) 65 60 55 50 45 40 35 30 25 20 15 10 5 0 -5 -10 -15 -20 0.6 0.8 1.0 Reset Ratio 1.2 1.4 1.6 1.
Appendix B (cont.) __________________________ Header Temperature for a Building Reference Temperature of 70°F Air Temp (0F) 0.6 0.8 1.0 1.2 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 -5 -10 -15 -20 70 73 76 79 82 85 88 91 94 97 100 103 106 109 112 115 118 121 124 70 74 78 82 86 90 94 98 102 106 110 114 118 122 126 130 134 138 142 70 75 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 70 76 82 88 94 100 106 112 118 124 130 136 142 148 154 160 166 172 178 B-4 Reset Ratio 1.4 1.
Appendix B (cont.) __________________________ Header Temperature for a Building Reference Temperature of 75°F Air Temp (°F) 0.6 0.8 1.0 1.2 Reset Ratio 1.4 1.
Appendix B (cont.) _________________________ Header Temperature for a Building Reference Temperature of 80°F Air Temp (°F) 80 75 70 65 60 55 50 45 40 35 30 25 20 15 10 5 0 -5 -10 0.6 0.8 1.0 1.2 80 83 86 89 92 95 98 101 104 107 110 113 116 119 122 125 128 131 134 80 84 88 92 96 100 104 108 112 116 120 124 128 132 136 140 144 148 152 80 85 90 95 100 105 110 115 120 125 130 135 140 145 150 155 160 165 170 80 86 92 98 104 110 116 122 128 134 140 146 152 158 164 170 176 187 188 B-6 Reset Ratio 1.
Appendix B (cont.) _________________________ Header Temperature for a Building Reference Temperature of 90°F ° Air Temp ( F) 0.6 0.8 1.0 1.
Appendix C _____________________________ Normal (Read-Only) Mode Display Messages and Defaults Key HDR TEMP (Press and Hold) AIR TEMP (Press and Hold) % LOAD SYS START TEMP (Press and Hold) REF TEMP (Press and Hold) HDR TEMP LIMIT (Press and Hold) SET POINT (Press and Hold) PROP BAND (Press and Hold) RESET RATIO (Press and Hold) OFF SET (Press and Hold) Display Message HEADER TEMP 160°F (Default Display) HEADER SET TEMP 160°F OUTSIDE AIR TEMP 70°F INDOOR AIR TEMP 70°F (If Connected) PERCENT OF LOAD 100
Appendix D _____________________________ Field Adjust Mode Display Messages and Defaults Key HDR TEMP (Press Once) (Press 2nd Time) (Press 3rd Time) (Press 4th Time) (Press 5th Time) (Press 6th Time) AIR TEMP (Press Once) (Press 2nd Time) Display Message RS485 BAUDRATE 9600 MIN SLAVE ADDR 0 MAX SLAVE ADDR 0 NUMBER NETW BLRS 0 MODBUS CNTL TYPE Round Robin NETW BOILER 1 ADDRESS=0 (Repeat for Each Netw Boiler) RS232 MODE MODBUS SLAVE RS232 BAUDRATE 9600 (Press 3rd Time) MODBUS ADDRESS 128 (Press 4th Time)
Appendix D __________________________ (cont.) Field Adjust Mode Display Messages and Defaults (cont.
Appendix E _____________________________ Config Sys Mode Display Messages and Defaults Key TEMP FAIL MODE SYS ENABLE MAX PWR INPUT (Press 2nd Time) START LEVEL STOP LEVEL BLR OP MODE (Press 2nd Time) If COMBINATION MODE is selected HDR SET MODE (Press 2nd Time) INTGL RATE GAIN TEMP BANDWIDTH AUX RELAY (Press 2nd Time) DERIV GAIN Display Message TEMP FAIL MODE SHUTDOWN INTERLOCK 1 START ENABLED MAX POWER INPUT 100% PWM TIMEBASE CAL 0 BLR.
Appendix F _____________________________ Temperature Sensor Resistance Data Temperature (°F) Resistance (ohms) Temperature (°F) Resistance (ohms) -40 -30 -20 -10 0 10 20 30 40 50 60 70 80 90 100 110 239,571 173,530 127,088 94,059 70,314 53,068 40,418 31,053 24,057 18,787 14,783 11,717 9,353 7,516 6,078 4,946 180 190 200 210 220 230 240 250 260 270 280 290 300 310 320 330 1,362 1,155 984 842 723 623 539 468 408 357 313 276 243 120 130 140 4,049 3,333 2,759 340 350 360 150 2,296 370 160 170 1
Appendix G _____________________________ Parts List Part Number GP-122783 Description Boiler Management System (BMS) 124376 Electronics GP-6-217 GP-6-218 GP-161228 GP-181108 GP-181109 #10-32 x 3/8 inch Mounting Screws #10-32 x 1/2 inch Mounting Screw Mounting Plate Field Adjust Overlay System Configuration Overlay 18949 Machined Front Panel 122784 Control Panel GP-122662 120 VAC, 1A, 2AG subminiature, fastacting fuse (Littlefuse 225001) 12 VAC, 5A, 2AG Subminiature, FastActing Fuse (Littlefuse
Appendix H _____________________________ TROUBLESHOOTING When a fault occurs in the boiler plant, the BMS flashes error messages at 2-second intervals and the alarm contacts close. To cancel alarms (open contacts but message still displays), press the RESET RATIO key The fault messages shown in Table H1 can occur in any mode of operation, Constant Setpoint, Indoor/Outdoor Reset, or Remote Setpoint. Some of the most common problems encountered in BMS operation are contained in Table H2.
Appendix H _____________________________ Table H1 Error Messages - Continued Fault Message Description & Possible cause SYSTEM ERROR, INTERLOCK 2 OPEN Interlock 2 is open (4-20 MA) INPUT OPEN LOOP ERROR The 4-to-20-mA remote input signal has dropped below 3 mA, or the signal is not present at the BMS. FAIL SAFE MODE ACTIVATED This message can be displayed when the BMS is controlling the boilers via Modbus or PWM communication.
Appendix H ____________________________ Table H2 Common Problems Problem Boiler plant not started by BMS Possible Causes • Outside air temperature higher than system’s start temperature • System must be initialized • Wiring between boilers and BMS not correct Boiler not being recognized by BMS with Modular Control Box Solution • Check outside air temperature and system start temperature. System start temperature should be higher than outside air temperature for boilers to run. See para. 4.3.3 and 4.3.
Appendix H _____________________________ Table H2 Common Problems - Continued Problem Boilers overshooting setpoint or tripping aquastat Modbus Network faults encountered. Boiler plant not operating Possible Causes Solution • Header sensor not installed correctly • Check header sensor connections and installation. • PID setting require adjustment • Adjust PID settings. See para. 4.4.7 • Adjustable aquastat set too low • If aquastat is set lower than 200°F, reset it to 220°F.
Appendix I _____________________________ GENERAL WIRING I-1
Appendix J _____________________________ PROGRAMMING THE BMS USING RS-232 COMMUNICATION Introduction The RS-232 port on the left side of the BMS can be used to program the BMS using a laptop computer or other suitable terminal. Connection to a laptop or other terminal device is made using a 9-pin RS-232 adapter cable. Communication can be accomplished using any “Dumb Terminal” emulation, such as Hyper Terminal which is included with Microsoft Windows.
Appendix J (cont.) __________________________ Programming Procedure BMS functions which can be viewed or changed are listed in Table J-1 along with their corresponding command numbers. Functions which can only be viewed (such as actual sensor readings) are marked “Read Only”. Viewing or changing function values is accomplished as follows: 1. Select the number of the desired command from Table J-1. 2. To view a parameter, type ?, followed by the command number and then press return ().
Appendix J (cont.) __________________________ Table J-1. BMS COMMANDS ENTRY RANGE FACTORY DEFAULT Header Temperature (°F) 40 to 220 Read Only 01 Outside Air Temperature (°F) -60 to 80 Read Only 02 Indoor Air Temperature (°F) 40 to 160 Read Only 03 Fire Rate (%) 0 to 100 Read Only 04 Header Set Temperature (°F) 40 to 220 Read Only 05 System Outside Air Start Temperature (°F) 32 to 120 70 06 System Start Mode No.
Appendix J (cont.) __________________________ Table J-1. BMS COMMANDS ENTRY RANGE COMMAND No.
Appendix J (cont.) __________________________ Table J-1. BMS COMMANDS – (Continued) COMMAND No.
Appendix J (cont.) __________________________ Table J-1. BMS COMMANDS – (Continued) 87 ENTRY RANGE COMMAND No.
Appendix J (cont.) __________________________ Table J-1. BMS COMMANDS – (Continued) No.
Appendix J (cont.) __________________________ Table J-1. BMS COMMANDS – (Continued) No.
Appendix J (cont.) __________________________ Table J-1. BMS COMMANDS – (Continued) ENTRY RANGE COMMAND No. FACTORY DEFAULT 124 Network Baud 2400, 4800, 9600, 14400, 19200 9600 125 Network Timeout 5 to 240 sec 126 Password Lo 0 to 255 0 127 Password Hi 0 to 255 0 128 Modbus Control Type 0 = Round-Robin 60 sec.
