AERCO C-More Controls Manual June 2010 - Manual (Page 117)

C-More Controller for Benchmark, Innovation & KC
USER MANUAL
04/22/14 AERCO International, Inc. • 100 Oritani Dr. • Blauvelt, New York 10913 Page 117 of 162
OMM-0032_0E Phone: 800-526-0288 GF-112
Whenever the Setpoint Setback time is reached (between Setback Start and Setback End), the
new setpoint (Setback Setpoint value) is activated to satisfy differing Heat-Demand during
certain times of the day.
The new Setpoint is activated on a gradual basis in order to avoid the PID from shutting down
units unnecessarily due to a sudden change in setpoint.
Setback Setpoint (Span = BST Setpt Lo Limit - BST Setpt HI Limit, Default = 130°F)
The Setback Setpoint item is the Setpoint value to be invoked when the Setpoint Setback
feature is activated.
Setback Start, Setback End (Span = 12.00am - 11.59pm, Default = 12.00am)
The Setback Start and Setback End items are the time values to define the time interval during
which the BST Setpoint is substituted by the Setback Setpoint value when the Setpoint Setback
feature is Enabled.
The same Setback Start and Setback End times apply to all 7 days of the week.
Rate Threshold (Span = 1 sec – 30 sec, Default = 15 sec)
The Rate Threshold is a BST feature that checks the operation of the PID control when a
boilers’ temperature needs to be increased by a large amount. If conditions change suddenly,
such as flow or load, when the temperature of a boiler is increasing, The Rate Threshold will
immediately decrease the boiler’s Fire Rate by 10% if the temperature is rising too quickly as we
approach the Setpoint. This feature will help prevent nuisance Temperature overshoots and
overtemp faults. If the temperature rises from15°F below Setpoint to 8°F below Setpoint within
the time value set in Rate Threshold, the rise rate will be deemed to be too quick and the Fire
Rate will be temporarily reduced by 10%.
This feature allows the temperature to rise in a normal manner until temperature approaches
setpoint. The feature is active ONLY when increasing temperature.
The feature is activated anytime the header temperature drops to 20 degrees F below the
setpoint.
NOTE
Setting the Rate Threshold value to 1 will effectively disable this
function.
9.5.4 OPERATE MENU
BST Next on VP (Span = 16% – 100%, Default = 50%)
When the Valve Position (VP) of all ignited boilers reach or exceed the BST Next on VP value,
another boiler will be lit off to share the load (if one is available).
This feature is also useful if a user wishes to always have as few boilers ignited at any one time.
Setting the BST Next on VP value to a high number (Example 99%) will only light off a new
boiler if all currently ignited boilers reach their total BTU capacity (99% Valve Position).
BST On Delay (Span = 30 seconds – 300 seconds, Default = 60 seconds)