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1 Service (continued) | J: Building Management System (BMS) | |
I: Cascade | ||
I1: 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 parameter I1. The outdoor air (if used), system supply sensor, and system return sensor must be connected to the Leader boiler. The default address is 1.
I2: Max. outlet set point
When the system supply sensor is connected, or the system supply temperature is provided through ModBus, this parameter determines the set point used by the individual boilers in a Cascade. When a boiler is commanded to fire by the Leader boiler, it will attempt to achieve this temperature at its outlet. The Leader boiler will limit the modulation of the last boiler to fire in order to hold the temperature at the system supply sensor to the user set point. If any of the boiler outlet temperatures reach the max. cascade set point, the boiler will then modulate down on its own in order to keep its outlet temperature within the max. cascade set point. Therefore, this parameter can be used to limit the outlet temperatures of all the boilers in a Cascade. Note that this parameter does not apply when the boiler is heating an indirect DHW tank. This parameter is adjustable by the installer by accessing parameter I2. The temperature range for this parameter is 32°F (0°C) - 261°F (127°C). The default max. cascade set point is 185°F (85°C).
I3: Cascade offset (boilers only)
This parameter determines how much the temperature must go above set point before the lead boiler will turn off. This parameter can be adjusted by the installer by accessing parameter I3. The temperature range for this parameter is 0°F (0°C) - 54°F (30°C). The default value is 9.9°F (5°C).
I4: Cascade differential (boilers only)
This parameter determines how much the temperature must go below the turn off temperature (Set point + Offset) before the lead boiler turns on. This parameter can be adjusted by the installer by accessing parameter I4. The temperature range for this parameter is 0°F (0°C) - 54°F (30°C).The default value is 19.8°F (11°C).
J1: BMS type
When the unit or cascade is controlled by the
J2: Voltage at minimum
This setting determines the voltage at which the external signal begins to increase either the modulation or the set point. Below this voltage, the modulation or set point will be at their minimum values. This parameter can be adjusted by the installer by accessing parameter J2. The range for this parameter is 0V - (J3 - 0.1V). The default value is 2V.
J3: Voltage at maximum
This setting determines the voltage at which the external signal forces either the modulation or the set point to their maximum value. This parameter, along with the previous parameter, determines how much the modulation or set point changes as the BMS input voltage changes. The modulation or set point will change in proportion to the change in voltage between the minimum and maximum voltage settings. This parameter may be adjusted by the installer by accessing parameter J3. The range for this parameter is (J2 + 0.1V) - 10V. The default setting is 10V.
J4: Power at low voltage
This setting determines the modulation of the unit or cascade when the BMS input voltage is at or below the Voltage at Minimum setting. This parameter is active only when the BMS type is set to Power. This parameter may be adjusted by the installer by accessing parameter J4. The range for this parameter is 0 - J5. The default value is 20%.
J5: Power at high voltage
This setting determines the modulation of the unit or cascade when the BMS input voltage is at or above the Voltage at Maximum setting. This parameter is only active when the BMS type is set to Power. This parameter can be adjusted by the installer by accessing parameter J5. The range for this parameter is J4 - 100%. The default value is 100%.
J6: Set point at low voltage
This setting determines the set point used by the unit or cascade when the BMS voltage is at or below the Voltage at Minimum setting. This parameter is only active when the BMS type is set to Set Point. This parameter can be adjusted by the installer by accessing parameter J6. The temperature range for this parameter is 32°F (0°C) - 230°F (110°C) (boilers), 32°F (0°C) to 190°F (87°C) (water heaters), or 32°F (0°C) to 105°F (40°C) (pool heaters). The default value is 70°F (21°C).
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