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COMMUNICATIONS 

HeatNet Control  REV 1.38-1

 

Page 55 

Figure 38 

MODBUS Input/Output Variables (Read/Write) 

Address 

Name 

Raw Data Type 

Scale 

Description 

Valid 

Values/Range 

40013 

SetHour 

8 bit unsigned 

--- 

Set real time clock – hour (

see SetClock

0 – 23 

40014 

SetMinute 

8 bit unsigned 

--- 

Set real time clock – minute (

see SetClock

0 – 59 

40015 

SetSecond 

8 bit unsigned 

--- 

Set real time clock – second (

see 

SetClock

0 – 59 

40016 

SetWeekday 

8 bit unsigned 

--- 

Set real time clock – weekday (

see 

SetClock

1 (Monday) - 7 

(Sunday) 

40017 

SetClock 

1 bit unsigned 

--- 

Set (write) the real time clock. 
Do Not Write more than once per minute 
To write the real time clock, the system 
variables (SetMonth, SetMonth, SetDay, 
SetYear, SetHour, SetMinute, SetSecond, 
SetWeekday) must first be loaded with the 
correct date and time.  Then, a 1 must be 
written to the state portion of this system 
variable to write the new date and time to 
the system clock. 

0 = no action 

1 = set/write the 

clock 

 

 

Figure 39 

MODBUS Input Variables (Read Only) 

Address 

Name 

Raw Data 

Type 

Scale 

Description 

Valid Values/Range 

30001 

BoilersOn 

8 bit 

unsigned 

--- 

The number of boilers currently 
running. 

0 – 16 

30002 

Modulation 

8 bit 

unsigned 

0.01 

Current system modulation level. 

0 – 100 % 

30003 

HeaderTemp 

16 bit 

signed 

0.01 

Header / System temperature. 

32 – 250 °F 

30004 

SupplyTemp 

16 bit 

signed 

0.01 

Supply temperature. 

32 – 250 °F 

30005 

ReturnTemp 

16 bit 

signed 

0.01 

Return temperature. 

32 – 250 °F 

30006 

OutsideTemp 

16 bit 

signed 

0.01 

Outside air temperature. 

-40 – 250 °F 

30007 

Spare1 

16 bit 

signed 

--- 

Raw A/D value from spare 1 input. 

-32768 to 32767 

30008 

Spare2 

16 bit 

signed 

--- 

Raw A/D value from spare 2 input. 

-32768 to 32767 

30009 

Month 

8 bit 

unsigned 

--- 

Real time clock month. 

0 (January) - 11 

(December) 

30010 

Day 

8 bit 

unsigned 

--- 

Real time clock day. 

1 – 31 

30011 

Year 

8 bit 

unsigned 

--- 

Real time clock year. 

0 – 99 

30012 

Hour 

8 bit 

unsigned 

--- 

Real time clock hour. 

0 – 23 

30013 

Minute 

8 bit 

unsigned 

--- 

Real time clock minute. 

0 – 59 

30014 

Second 

8 bit 

unsigned 

--- 

Real time clock second. 

0 – 59 

30015 

Weekday 

8 bit 

unsigned 

--- 

Real time clock weekday. 

1 (Monday) – 7 (Sunday) 

30016 

Boiler01Status1 

16 bit 

--- 

Boiler (1 – 16) status flags.  These 

See the “BoilerStatus1” 

Summary of Contents for Smith Series

Page 1: ...can only be operated with a dust free air supply Follow the instruction manual procedures to duct air to the boiler air intake If the boiler has been contaminated by operation with contaminated air fo...

Page 2: ...XED BOILERS 13 MIXED SYSTEM EXAMPLES 13 BASE LOADING RELAY CONTROL 17 SETTING UP BASE LOADING 18 Heating Control Methods 20 HEATING METHOD 1 20 HEATING METHOD 2 20 HEATING METHOD 3 20 HEATING METHOD 4...

Page 3: ...ced Menu Tree Smith Version 1 38 69 Worksheet 70 Thermistor Resistance Temperature Table 73 Status Screen Fault Display 75 Line 4 Log Entries 78 Information contained in this publication regarding dev...

Page 4: ...unction The control will continue to function and report the fault but its ability to control the boiler will end Each Smith boiler employing this control can function as either a master or a member T...

Page 5: ...t water temperature is also monitored If the outlet temperature approaches the operating limit temperature setpoint adjustable the boilers firing rate is limited and its modulation value is reduced to...

Page 6: ...nterface 16 Alarm Relay dry contacts and Audible Alarm 17 Runtime hours and Cycles based on Main Valve Open 18 Outdoor Air Reset with programmable setpoint and ratio 19 Time of Day clock to provide up...

Page 7: ...VAC resistive K8 on J4 1 2 for Base Loading and Dual Fuel 1 4 Amp AC Interlocks 24 VAC 120 VAC input Control Inputs AA Heat Demand 4 20ma Enable OA override T1 T2 dry contact inputs 4 20mA 0 10 VDC 2...

Page 8: ...02 4285 Sensor with well ACI CP I 2 5 02 4286 Sensor with well ACI CP I 4 02 4281 Strap on sensor ACI 10k CP S 02 4280 Outside Air Sensor with Housing ACI 10k CP O Installation Operation Manual 40 54...

Page 9: ...ntimes to determine which boiler has the least runtime based on the MIN RUNTIME setting in ADVANCED SETUP FIRING MODE The MIN RUNTIME setting is the minimum runtime interval in hours that is used to c...

Page 10: ...nomy A boiler set can be constructed by simply setting the firing priority on each boiler to be in a set at the same priority Setting all example condensing boilers to the highest priority of 1 and th...

Page 11: ...priority boiler set may be configured here Temperatures are adjustable Once the conditions menu has been entered the firing order and stop order of the priority 1 boiler set can be selected based on u...

Page 12: ...emp if the difference temp is not required Start Stop settings Any combination of Start Conditions and Stop Conditions can be used to optimize the mixing of condensing Priority 1 and non condensing bo...

Page 13: ...amples using the Boiler System Response graphs The Smith Mixed Boiler System examples is advantageous in providing low BTU input for light loads and high BTUs for heavy loads The effective system turn...

Page 14: ...AX value to allow a guard band tolerance 4 If boilers are of different sizes try to use larger priority 2 boilers 5 If the calculated Mod MAX value is greater than 99 the combination can not be used s...

Page 15: ...000 4 000 000 5 000 000 Input System Load Btu Hr Blr 1 2 1200 MBTU Blr 1 2 3 4 3512 MBTU Blr 1 2 3 2356 MBTU Figure 9 Boiler System Response 1 chart illustrates how each boiler in the example is brou...

Page 16: ...ample system uses 2 KN6s and 2 28A W 5s Two of the KN6s are treated as one when adding the min inputs of the Priority 1 set Figure 12 Boiler System Response 4 2 KN6 s 2 28A W 5 s 85 Mod Max 0 00 0 10...

Page 17: ...he boiler can start again Once this time expires the DELAY TIME also needs to expire to start the boiler This will help in minimizing short cycle conditions and can be set at ADVANCED SETUP FIRING MOD...

Page 18: ...r The default setting is for the Base Load boiler to stop first once the water temperature exceeds the top of the heating band Figure 14 Base Load Relay Wiring Base Load RIB Relay 24 VAC 24 VAC Return...

Page 19: ...sable the boiler when the OA T read from the Outside Air Temperature sensor if equipped rises above this value ADVANCE SETUP BASE LOADING STOP OA T If the OA T qualifier is used as the Start and Stop...

Page 20: ...rotect itself from short cycling by limiting the firing rate coming from the Master This occurs in the event that the member s supply temperature increases above the OPERATE LIMIT OPERATE LIMIT BAND O...

Page 21: ...C signal by each boiler The temperature of the water is maintained by sending this signal to the Mod Motor which in turn controls the damper position and fuel rate providing the firing rate control Me...

Page 22: ...inimum fire rate of 25 If the MINIMUM setting of the boiler is set above the example 4 1 turndown of 25 such as 33 a control signal change between 25 and 33 will not change the boilers firing rate Onc...

Page 23: ...signal is sensed the boiler will initiate a start sequence and fire the boiler at its minimum setting if the REMOTE ENABLE input is closed This is typically 33 3 1 turndown or 25 4 1 turndown of the b...

Page 24: ...setting has been met when using OUTDOOR AIR RESET 2 The second mode will allow the circulator pump to be turned on whenever there is a call for heat any control input This mode will stop the circulato...

Page 25: ...o be used for the damper prove switch when a common system damper is used If you use terminal 8 to supply power from the Maste r and the Master is powered OFF no boiler will be allowed to fire due to...

Page 26: ...ry 10 minutes in an attempt get the boiler restarted The damper fails to open and never closes its proof switch a retry algorithm will attempt a retry Every 10 minutes the damper relay will cycle and...

Page 27: ...s from the MASTER boiler is re established Ensure that this Member boiler s Damper and System pump control are configured correctly with the assumption that the Master is not powered Also ensure that...

Page 28: ...mperature to the setpoint post purge time of the DHW pump Setting up this method is done via the menus in SETUP DOMESTIC HOT WATER 1 Connect a 10k thermistor from the DHW tank s sensor well to J10B te...

Page 29: ...TPOINT to the desired target temperature of the water in the tank Once the control determines there is a call for DHW the DHW SETPOINT is loaded and the Master boiler will target this new setpoint 4 N...

Page 30: ...ensure that all boilers are shut off at the upper point of the heat band set the SHED BOILER DELAY time to 0 This will effectively turn off all boilers at the upper heat band point of example 145F Now...

Page 31: ...defined threshold The Stack Temperature is monitored since it is a good indicator of the boilers health The sensor that measures this temperature is a 1k ohm RTD type sensor which can handle the highe...

Page 32: ...ed on the flash drive press and hold the BACK key for 5 seconds to enter the Setup menus Select the ADVANCED SETUP SYSTEM LOAD FIRMWARE Select YES using the arrow keys and press the SELECT key Select...

Page 33: ...WIRING CONNECTIONS HeatNet Control REV 1 38 1 Page 33 Wiring Connections Figure 26 Power Connections...

Page 34: ...4 V D C 2 4 V D C 0 1 0 V D C 1 1 8 I N T E R L O C K S R E T A B G A B G A B G S e n s e 2 4 V A C L 2 L 1 L 1 3 P O W E R S E R V I C E L 2 A C G N D 1 O U T P U T 0 1 0 V D C I G N I T I O N C O N...

Page 35: ...DC SPARE 2 WTR OUT OUTSIDE 0 10VDC EXT OPERAT VFD WTR FLW GAS PR SYSTEM 24V 24V BOILR START 24VAC TRANSFORMER PILOT VALVE MAIN VALVE HIGH LIMIT Unused 4 20ma PWM 0 10 1 1 8 AIR WTR IN AIR PR SW VALVE...

Page 36: ...12A J12B J13 J 1 0 A F 1 J 4 J 1 6 J18 J 1 9 J 1 4 K1 K4 K5 K6 K2 BZ1 J P 3 K1a T 7 7 _ R E L A Y K2a T 7 7 _ R E L A Y K4a T 7 7 _ R E L A Y K5a T 7 7 _ R E L A Y K6a T 7 7 _ R E L A Y J10 J 1 1 J 1...

Page 37: ...FD OUTPUT O U T P U T DHW PUMP D H W T A N K AUX STATUS Aux Status PUMP VALVE M O D B U S H N E T A L R M R S T D A M P E R H E A D E R R E T U R N S U P P L Y P W M 0 1 0 4 2 0 m a 8 SPARE 4 LWCO KNS...

Page 38: ...O N T R O L Unused 1 1 1 1 J u m p e r2 3 fo r1 3 5 o h m 2 3 HEAT NET K 8 J 2 2 J 2 0 J 6 D 5 D 4 K7a T 7 7 _ R E L A Y K7 J 2 S 4 S2 SIP1 2 0 1 9 1 2 J9 F 3 J 1 0 B U 2 6 J12A J12B J13 J 1 0 A F 1...

Page 39: ...B G S e n s e 2 4 V A C L 2 L 1 L 1 3 P O W E R S E R V I C E L 2 A C G N D 1 O U T P U T 0 1 0 V D C I G N I T I O N C O N T R O L J u m p e r2 3 fo r1 3 5 o h m J 2 2 J 2 0 J 6 D 5 D 4 T 7 7 _ R E...

Page 40: ...e n s e 2 4 V A C DHW PUMP LOWFIRE L 2 L 1 L 1 3 P O W E R S E R V IC E L 2 A C G N D 1 02 2008 OPERATOR O U T P U T 0 1 0 V D C W B R MODULATION CONTROL 4 20mA BLOWER M I G N I T I O N C O N T R O L...

Page 41: ...4VAC TRANSFORMER PILOT VALVE MAIN VALVE HIGH LIMIT Unused 4 20ma PWM 0 10 1 1 8 A I R W T R I N AIR PR SW VALVE ALRM FLAME SAFE I N T E R L O C K S ENABLE HIGH FIRE R E T 4 20mA CAL NORM PWM 0 10 WTR...

Page 42: ...AMPER 24 VAC Transformer DAMPER Prove Switch DAMPER Enable 24 VAC Mains MASTER BOILER MEMBER BOILER 1 Connection if Member boiler is running as Failsafe MEMBER BOILER 2 Connect to 24 VAC Return on eac...

Page 43: ...lsafe Common System Pump Wiring System Pump Contactor System Pump Voltage Feed System Pump System Pump Voltage Return 120VAC Ph2 Ph3 120 Return System Flow Prove Switch 120VAC MASTER BOILER MEMBER BOI...

Page 44: ...es can be changed while running ONLY IN MINIMUM FIRE any but only one of the T inputs closed Prior to ignition the values may be changed but the blower will not operate Press the arrow keys until MIN...

Page 45: ...ate is defined as the Boiler s that is running the Circulator Pump state and the ignition condition Main Valve Pilot Valve Blower and the Ignition alarm The of boilers that are displayed is limited to...

Page 46: ...Setpoint is used 4 20mA input is mapped to a setpoint OUTDOOR AIR RESET OA RESET OFF Outdoor reset ratio boiler water temp outside air temp WARM WEATHER SD NO If set to YES the boiler system shuts do...

Page 47: ...efore proving flow NIGHT SETBACK SETBACK ENTRY 1 1 4 Four setbacks to adjust setpoint during a time period ENTRY IS OFF Enable or disable the use of this setback SETBACK 20 F 0 50 F Temporarily subtra...

Page 48: ...f Using J12B in a common damper configuration wiring is done beginning with the Master boiler J12B Pins 7 8 are connected to the prove switch of the combustion damper Pin 8 is supplying 24 VAC and pin...

Page 49: ...e delta T s If this Master boiler is running LOW TEMP HOLD 130 F 130 160 F The boiler will be held in low fire until the return temperature exceeds the set value The default is 130F but can be increas...

Page 50: ...ded If a second boiler needs to stop the SHEDBOILER DELAY will need to expire before stopping MODULATE DELAY TIME 10 secs 0 60min This is the time the boiler remains in min fire before it relinquishes...

Page 51: ...0s Once the Main Valve opens on the newly added boiler and the MOD MODE ADAPTIVE the Master waits this amount of time before releasing the PID to control modulation This allows for the newly added bo...

Page 52: ...rforms the tasks of the MASTER boiler If the HEADER sensor is set to NONE its function is the MEMBER The remaining 2 sensors perform as user selections and provide functions such as Combustion Air Pro...

Page 53: ...settings used by the MIXED boiler rotation algorithm Priority 2 is the default and lowest priority Priority 1 is the highest priority A Priority may be assigned to a set of boilers which fires and rot...

Page 54: ...he system setpoint When the timer reaches zero the control assumes that the BMS is no longer operating and the local setpoint saved on the control is reloaded This is a failsafe feature used to help s...

Page 55: ...les Read Only Address Name Raw Data Type Scale Description Valid Values Range 30001 BoilersOn 8 bit unsigned The number of boilers currently running 0 16 30002 Modulation 8 bit unsigned 0 01 Current s...

Page 56: ...ler15Status2 30046 Boiler16Status1 30047 Boiler16Status2 30048 Boiler01RuntimeHigh16 16 bit unsigned Boiler 1 16 Runtime seconds High Upper and Low Lower 16 bit counters To get the actual runtime for...

Page 57: ...r02SupplyTemp 30098 Boiler03SupplyTemp 30099 Boiler04SupplyTemp 30100 Boiler05SupplyTemp 30101 Boiler06SupplyTemp 30102 Boiler07SupplyTemp 30103 Boiler08SupplyTemp 30104 Boiler09SupplyTemp 30105 Boile...

Page 58: ...yclesHigh16 30149 Boiler11CyclesLow16 30150 Boiler12CyclesHigh16 30151 Boiler12CyclesLow16 30152 Boiler13CyclesHigh16 30153 Boiler13CyclesLow16 30154 Boiler14CyclesHigh16 30155 Boiler14CyclesLow16 301...

Page 59: ...unning 6 Pump Running 0 off 1 running 7 Spare 3 Interlock 0 open 1 closed 8 LWCO Interlock 0 open 1 closed 9 VFD Interlock 0 open 1 closed 10 Gas Prove Interlock 0 open 1 closed 11 Spare 4 Interlock 0...

Page 60: ...r Reset Override 0 off 1 on 4 T1 0 off 1 on 5 T2 0 off 1 on 6 T3 0 off 1 on 7 T4 0 off 1 on 8 reserved for future use 9 reserved for future use 10 reserved for future use 11 reserved for future use 12...

Page 61: ...s to be disabled in the AUX FUNCTIONS menu Situation The display is displaying random characters or the control keeps resetting There may exist a grounding problem with the controller or one of the bo...

Page 62: ...ion Only the MASTER boiler Fires but the system has many boilers and is using H Net 1 In order for the MASTER boiler to act as a MASTER the header sensor must be set to TYPEZ and there must be a heade...

Page 63: ...blower speed and in the operating limit band there may be not enough flow through the boiler or the Operating Limit Operating Limit Band may be improperly set The Operating Limit Operating Limit Band...

Page 64: ...he polarity to determine the proper connections A ground wire must always be used and a shielded twisted wire is STRONGLY suggested Situation We are using a Building Management System BMS to control t...

Page 65: ...OPERATION HeatNet Control REV 1 38 1 Page 65 Smith Series Run Screen...

Page 66: ...re please see the Default Settings Menu Item Descriptions SETUP starting on page 46 Status information screens This screen indicates that the boiler s SUPPLY Temperature has gone above the OPERATOR LI...

Page 67: ...time has not expired This Screen indicates that the boiler s input is temporarily being limited to optimize the boiler s efficiency This screen indicates that the boiler is running in LOCAL MODE beca...

Page 68: ...OPERATION HeatNet Control REV 1 38 1 Page 68 Smith Series Menu Tree Version 1 38...

Page 69: ...DELAY TIME 4 MINUTES SHED DELAY TIME 2 MINUTES 0 SECONDS MODULATE DELAY TIME 0 MINUTES 10 SECONDS STOP MOD MAX 70 MOD MODE ADAPTIVE DROP DOWN ON PILOT DELAY RELEASE 0s 4 20mA INPUT BOILER START 4mA S...

Page 70: ...A TEMP WATER TEMP LOW OA TEMP PUMP OPTIONS SYSTEM PUMP POST PURGE TIME ALWAYS ENABLED SUMMER PUMP JOG LOCAL PUMP DELTA TEMP ENAB DELTA TEMP POST PRGE TIME s ALWAYS ENABLED PUMP VALVE OPTION REMAINS ON...

Page 71: ...71 TYPE IN USE INPUT PROOF TIME ALARM SILENCE SWITCH IN USE INPUT FAILSAFE MODES H NET COMM LOST LOW TEMP TEMP HEAT EXCHANGER EXCHGR DELTA T 40F LIM HALF RATE DHW SETPOINT DHW DIFF USE SENSOR DHW PRI...

Page 72: ...LAY RELEASE FIRING MODE MODE MIXED START PRIORITY 1 SET STOP PRIORITY 1 SET MIN RUNTIME MIN OFF TIME PREDICT START BASE LOADING BASE LOAD BOILERS START MOD STOP DELAY TIME SENSORS SENSOR OUTDSIDE SUPP...

Page 73: ...13 130 410 75 167 1 479 20 4 97 072 80 176 1 255 15 5 72 951 85 185 1 070 10 14 55 326 90 194 915 4 5 23 43 326 95 203 786 6 0 32 32 650 100 212 678 6 5 41 25 391 105 221 587 6 10 50 19 899 110 230 51...

Page 74: ...6 150 1 254 249 480 1 937 432 810 2 581 71 160 1 275 254 490 1 957 438 820 2 600 77 170 1 296 260 500 1 977 443 830 2 619 82 180 1 317 266 510 1 997 449 840 2 638 88 190 1 339 271 520 2 017 454 850 2...

Page 75: ...the input to the High Limit Control SPARE 4 This is a reserved interlock input that is user defined The interlock is located on J5B SPARE 4 LOW WATER CUTOFF If there is a low water condition reported...

Page 76: ...ime specified in the combustion air damper menu the boiler will not start and then display the fault A combustion damper fault on a boiler can only be cleared by power cycling OPEN SENSOR If the open...

Page 77: ...rature exceeds 550 F this message will be displayed If the stack temperature continues to rise above 700 F the boiler will be held in low fire CALL SERVICE If the H Net control closes the last interlo...

Page 78: ...FAIL If the combustion air damper is used and does not prove across J12B DAMPER this message is displayed SYSTEM RESET O stack overflow U Stack Underflow both are software faults R Reset Instruction F...

Page 79: ...faults are result of the interlocks connected to the 24VAC interlock inputs J11A and J11B Low Water Cutoff Low water condition in boiler Var Freq Drive The Variable Frequency Drive Interlock has trip...

Page 80: ...LOST FAIL SAFE LOW TEMP If the Fail Safe modes are active these log entries indicate that they became active for some reason and the boiler had entered Fail Safe mode BASE LOAD BOILER The Base load B...

Page 81: ......

Page 82: ...Smith 260 North Elm Street Westfield MA 01085...

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