Installation & Operation Manual

11 Operating information (continued)

Cascade (continued)

If the water temperature at the system supply sensor is less than the set point + the turn-off offset - the off-on differential, then the control will initiate a call for heat on the Cascade (see the Knight XL Service Manual for an explanation of the offset and differential). The Leader will energize the lead boiler on the Cascade. For a new startup this will be the Leader boiler.

The boiler will fire at its ignition speed and will then modulate its firing rate to maintain the set point. If the first boiler reaches 100% of its firing rate, the Leader will calculate at what point the second boiler could fire at 20% of its firing rate. At this point, the Leader will fire the second boiler on the Cascade. For a new startup, this would be the first Member boiler. The boiler will fire at its ignition speed and will then modulate its firing rate to maintain the set point.

If the set point still cannot be met, the Leader will continue firing more Members until either the heat demand is met or all boilers on the Cascade are firing. As the heat demand decreases, the last boiler on will modulate down to 20% of its firing rate. Once the demand for that boiler is zero, it will shut down. As the heat demand decreases further, the second to last boiler will modulate down and shut off. This will continue until the demand is satisfied and all boilers are shut off.

Sequence of the cascade

To equalize the run time of all boilers on the Cascade, the firing sequence will automatically be changed at set intervals.

For the first 24 hours after initializing the Cascade, the sequence will be changed every hour. After that the sequence will be changed once every 24 hours. The switching on/off sequence will be as follows:

DHW, Night Setback, and Ramp Delay operation with

cascade

For DHW operation any boiler(s) in the Cascade can be selected to provide heat for a DHW call. Select a boiler to be designated as the DHW boiler. Connect the DHW thermostat to the terminals on the Low Voltage Connection Board marked for the DHW Thermostat. When the boiler receives a DHW call, the Leader control will take that boiler out of the Cascade sequence. If another boiler is available, the Leader will start it up to take its place.

The DHW boiler will adjust its set point to the programmed DHW set point and will adjust its firing rate to maintain this. Once the DHW call has been satisfied, the Leader control will place that boiler back into the Cascade sequence.

Switching of the boiler between DHW operation and SH operation when there is a call for both does not occur. The boiler will provide heat for the DHW demand until it is satisfied.

Night Setback operation of the boilers within the Cascade is available. Programming of the Night Setback will be done through the Leader boiler. Refer to the Knight XL Service manual for information regarding Night Setback.

Ramp Delay operation of the boilers as described in the Knight XL Service Manual is not active when the boilers are part of a Cascade system.

DAY

SWITCHING ON SEQUENCE

 

 

Day 1

L-M1-M2-M3-M4-M5-M6-M7

 

 

Day 1 + 1 hour

M1-M2-M3-M4-M5-M6-M7-L

 

 

Day 1 + 2 hours

M2-M3-M4-M5-M6-M7-L-M1

 

 

59

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Image 59
Lochinvar 399 operation manual Sequence of the cascade, DHW, Night Setback, and Ramp Delay operation with Cascade
Page 58 Page 60

399 specifications

Lochinvar 999 - 750, CF-CH(E)-i&s-08,399 is a cutting-edge boiler designed for commercial heating applications. With its robust construction and high efficiency, this model stands out in the crowded market of heating solutions.

One of the main features of the Lochinvar 999 - 750 is its exceptional thermal efficiency rating. The unit incorporates advanced condensing technology that allows it to recover heat from flue gases, which helps in achieving efficiency levels of up to 99%. This efficiency not only reduces energy consumption but also lowers operational costs, making it an excellent investment for businesses looking to minimize their carbon footprint.

The boiler is designed to provide a powerful output of 750 kW, ensuring it meets the heating demands of larger buildings or commercial spaces. Its capacity makes it suitable for a range of applications including schools, hospitals, and industrial facilities. Moreover, the unit features a built-in cascading system that enables multiple boilers to be connected, enhancing system reliability and flexibility.

In terms of technology, the Lochinvar 999 - 750 is equipped with a user-friendly touchscreen interface. This innovative control system allows operators to monitor and adjust settings with ease, providing real-time performance data and alerts for maintenance needs. The intelligent controls optimize operation to match the heating load, further enhancing energy efficiency.

Safety is a top priority with this model. It is built with multiple safety features such as automatic shut-off valves, pressure relief valves, and flame monitoring systems, ensuring safe operation under various conditions. The unit also adheres to stringent industry standards and regulations, making it a reliable choice for commercial applications.

Furthermore, the Lochinvar 999 - 750 is designed with serviceability in mind. Its compact footprint and accessible components simplify maintenance, reducing downtime and associated costs. The unit also supports a variety of fuel sources, including natural gas, propane, and biodiesel, providing flexibility to meet different facility requirements.

In summary, the Lochinvar 999 - 750, CF-CH(E)-i&s-08,399 represents a blend of efficiency, reliability, and safety in commercial heating. Its advanced technologies and thoughtful design make it a powerful solution for various heating needs, making it an ideal choice for businesses aiming for excellence in energy management and operational efficiency.
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