watkinsdr wrote:I currently have my S260 PLC SV at the 140 degree "factory setting." You recommend trying a higher setting, i.e. 145-150?
I believe the "factory setting" is 130--not 140.
The following is taken from a 2009 AHS Manual:
"The ash temperature monitoring control incorporates a digital process controller for operating the coal grate motor based on ash temperature in the grate area. This process offers significant advantages, including the following: It maintains active monitoring of grate temperature during periods of low demand. This monitoring, and subsequent cycling of grates, takes place whether the boiler fan operates or not. This control also reduces the likelihood of unburnt coal being dumped into the ash pan.
This control is factory set to 130° F and should not be adjusted to more than 10° F higher or lower than the factory setting for best operation (refer to Appendix G for instructions). When reading the digital readout, PV refers to the process variable, or actual ash temperature reading. SV refers to the setpoint variable, or the temperature setpoint of the control. Based on factory settings, when the temperature of the ash drops to 10° F below the reading indicated at SV the grates will cycle on, operating until ash temperature climbs to the SV value."
The following is taken from a different section of the 2009 Manual:
"THERMO ASH-MONITORING GRATE CONTROL OPERATION
Ash that contains fuel that is not fully combusted will be a higher temperature than ash coming from thoroughly combusted fuel. The Thermo Ash-Monitoring Control automatically monitors the temperature of the ash leaving the coal pot. This provides a feedback mechanism for grate regulation that reduces the need for post install adjustments. Typically, no adjustment other than the factory adjustment is necessary to have the boiler perform at peak power output throughout the burn season (a minor on-site adjustment may be necessary when the boiler is first installed). With the Thermo Ash Monitoring controlled grate, it is possible for the fire to remain lit for days during low usage periods without having to adjust the grate controls by hand, as would be necessary in a timer-based grate control system.
If an ash temperature sensor is used, it should be set at 130° for normal operation. During periods of light demand, reducing the setting to 120° will aid in maintaining the proper level of coal in the coal pot."