1 Service (continued)
Ramp Settings
NOTICE | Please note that the brackets ([]) denote |
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The SMART SYSTEM control can be programmed to limit the firing rate for a fixed period of time at the start of a space heating demand. There are six (6) possible limits, each with their own time delay. The first limit applies as soon as the burner starts. Once its time delay expires, the second limit is applied and its timer begins. The control steps through these limits until the 6th (sixth) limit expires. Note, however, that the 6th limit will also limit the rate for the rest of that heat demand. The installer can adjust the firing limits and time delays by accessing the Ramp Settings parameter. Once this parameter is selected, the screen will show the step number, the time delay for that step and the limit value corresponding with that step. If the installer wishes to adjust one of the values in that step, he can press the NAVIGATION dial until the value he wishes to change is flashing. The installer can then rotate the NAVIGATION dial to adjust that value. If the installer presses the RIGHT SELECT [SAVE] key while the limit value is flashing, the step value will flash again. The installer can then select the next step and adjust the delay and limit values corresponding with that step.
When finished, the installer can press the RIGHT SELECT [SAVE] key to store the new settings, or the LEFT SELECT [EXIT] key to return to the Anti-Cyclingparameter list without saving the changes. The delay value can be set between 0 minutes and 20 minutes. The limit value can be set between 0% and 100%.
Control modes
Controlling Sensor
The SH controlling sensor parameter selects the sensor the control will use to regulate the boiler firing rate. This parameter is adjustable by the installer by accessing the Controlling Sensor parameter. The sensor selections are as follows: The outlet sensor regulates the firing rate based on the outlet water temperature of the boiler and the inlet sensor regulates the firing rate based on the inlet water temperature of the boiler. If the outlet sensor is selected, and the optional system supply sensor is connected, the control will regulate the firing rate based on the system supply sensor temperature. The default sensor is the Outlet Sensor.
BMS Thermostat Input
When controlling the boiler through the 0 - 10V BMS input or through ModBus, the boiler can be enabled one of two ways. With the BMS Thermostat Input parameter set to ACTIVE, the boiler will be enabled by closing the Heat/Loop Demand 1 input. When set to INACTIVE, the boiler will be enabled by the voltage level on the 0 - 10V input (in the case of 0 - 10V BMS control), or the 0 - 10V input value received through ModBus. The default value is INACTIVE.
Service Manual
BMS
The set point or modulation of the boiler may be controlled through the 0 - 10V BMS input or through ModBus. When the BMS parameter is set to INACTIVE, the 0 - 10V input will be ignored. When set to ACTIVE, the set point or modulation will be controlled by the voltage on the 0 - 10V input (in the case of 0 - 10V BMS control), or the 0 - 10V input value received through ModBus. The default value is INACTIVE.
ModBus
When BMS is set to ACTIVE (see BMS Active / Inactive) and the boiler is being controlled through ModBus, set ModBus parameter to ACTIVE. Otherwise, set the ModBus parameter to INACTIVE. Note that the boiler can still be monitored by ModBus with this parameter set to INACTIVE. The default value is INACTIVE.
ModBus T/O
The amount of time the unit controls will wait to receive a communication string from the BMS controller before reverting back to its own internal parameters. This parameter is adjustable by the installer by accessing the ModBus T/O parameter. The adjustment range of this parameter is 5 seconds to 2 minutes. The default value is 10 seconds.
Cascade Address
The boiler designated as the Leader needs to be programmed with address 0. All the Member boilers require addresses from 1 to 7, and the addresses must be different for each Member. The addresses can be in any order, regardless of the order in which the units are wired together. This parameter is adjustable by the installer by accessing the Cascade Address parameter. The outdoor air (if used) and system supply sensor must be connected to the Leader boiler. The default address is 1.
If installing the boilers in an existing system, the new boilers should be programmed as the Leader and/or the higher number addresses.
Cascade Type (L/L / EFF)
There are two (2) options for the way a Cascade divides the load between its heaters. The first is Lead/Lag, designated as L/L in the menu. This method is used when it is desired to have the least amount of total flow through the boilers. This method will modulate the last two (2) boilers. This provides for smooth transitions when a boiler turns on or off. When the last boiler reaches 100% and the calculated load is still increasing, it will start the next boiler at 20% and reduce the previous boiler to 80%, thus eliminating the sudden jump in total output of the Cascade. When the calculated load is decreasing and the last boiler gets down to 20% fire, it will hold it there and start lowering the firing rate on the next-to-last boiler. When the next-to-last boiler reaches 20%, it will turn the last boiler off and raise the rate of the next-to-last boiler to 40%, thus eliminating the sudden drop in total output of the Cascade.
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