Bryan Boilers 250, Triple-Flex 150, & 300, 200 service manual LEAD-LAG Operation

4.4LEAD-LAG OPERATION

This is a summary of the functional capability of the embedded lead-lag on the Sola control. OEM Configurable parameters may be adjusted as part of the OEM factory configuration and in the field using the System Display with appropriate password permissions. Specific parameters may also be configured in the field by the local display 1. Field Installation Configuration a. The master and slave controllers are enabled via the S7910 or S7999 display. b. All Sola controllers are programmed with a default address of 1. Assuming the Master Sola controller remains address 1, the address of the slave controllers in the system must have a unique address (1..8) via the local display. 2. Basic Operation a. Firing rate determination – Parallel common-base limited

(1)All boilers have a single assignable base load firing rate. (2) Allocation (a)As load increases: (i) Until all stages are Firing - No stage is requested to exceed the common base load rate. (ii)After all stages are Firing - There is no restriction on the slave's commanded firing rate. (b)As load decreases: (i) As long as all available stages are firing - There is no restriction on the slave's commanded firing rate. (ii)When at least one stage has been dropped - No stage is requested to exceed the common base load rate. b. Rotation (1) The lead boiler is rotated based sequence order. The lead boiler rotation time is a configurable OEM assigned parameter. Rotation is sequential by address (1- 2-3-4; 2-3-4-1; etc.) (2) Rotation trigger occurs at the start of each new heat cycle. c. Source of heat for call – The call for heat originates at the master boiler. This source may be configured to be an external thermostat or via EnviraCOM Remote Stat. d. Slave boiler lockout – If any slave is in lockout the master boiler will cause it to be skipped and all system load setting calculation settings will be based only on available boilers. e. Master boiler lockout – If the master boiler is in lockout then its burner control function will be skipped in the rotation the same as the slave controllers. However, the master boiler function will continue to operate. 3. System Component Failure Responses a. If the system header sensor becomes disconnected from the master boiler then the master boiler will control off of one of the following OEM configurable actions (1) Disable - No backup will

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Date: 8-4-2010

Revision: 0

Form: 2396

be used (a)Lead Outlet - Outlet temperature of the lead boiler will be used as the backup during firing (i) Slave Outlet Average - Average of the outlet temperatures of all slave boilers that are firing will be used as a backup (b) If the sensor chosen by the above parameter is faulty then the backup sensor provided may be used. When burner demand is off and no burners are firing then, for either "Lead Outlet" or "Slave Outlet Average", the lead boiler's outlet temperature is used to monitor for burner demand. 4. Local Display Configuration and Operation a. The configuration parameters available on the local display are edited in the Service Mode b. Access to the Service Mode is accomplished by pressing both up/down buttons for 3 seconds. c. Status and Operation (1) Slave status (a) “Rmt” and “Adr” icons are on to show slave (follower) has been enabled. (b)Current burner status is shown (c) To show slave CFH (i) Alternate “%” firing rate and actual (slave) Outlet temp to indicate slave CFH otherwise show the Home screen. (2) Master status (a)Rmt icon is on, Adr icon is off to show Master (Leader) has been enabled. (b)Current burner status is shown (c) Actual temperature LL (Header) temperature is shown as described in 4e below. (d)Pressing the up/down buttons allows setpoint adjustment for LL-CH only (not LL-DHW or LL-Mix or others). (i) All pump configurations must be done using the PC Configuration tool in the OEM factories. (e)To show Master CFH (i) Alternate “CH” or “LL” or “Hdr” in numbers field with the actual temperature to indicate LL CH CFH. d. Configuration (1) Continue scrolling through set- up screens until “Remote Firing Control” screen is reached. (2) Rmt On/Off selection chooses to navigate the user through the Master/Slave configuration as existing today (3) Set master/slave remote address as is done on currently on the local display. (4) The following parameters are mapped to Modbus addresses. LEAD LAG 5 66—A1171(a) “LL” = LL Operation (3 user selections available) (i) “Ldr” (i-a)Master Enable (i-b)Slave Enable (ii)“SLA” (ii-a)Slave Only Enable (ii-b)Master Disable (i) “OFF” (iii- a)Master Disable (iii-b)Slave Disable (b)HS = On/Off Hysteresis (One value used for all LL boilers) (i) “HS” for on and off hysteresis values. (i-a)Only allow 1 setting for both on and off hysteresis values. (a-1)Must adhere to the strictest of either the HS On or Off limits. • Highest value of the “low” range limit in Sola control • Lowest value of the “high” range limit in Sola control (a-2)See Sola Modbus specification for details. • Typical values: 2-15 (c) BL =