11 Operating information

General

How the boiler operates

The Knight XL uses an advanced stainless steel heat exchanger and electronic control module that allows fully condensing operation. The blower pulls in air and pushes flue products out of the boiler through the heat exchanger and flue piping. The control module regulates blower speed to control the boiler firing rate. The gas valve senses the amount of air flowing into the boiler and allows only the right amount of gas to flow.

How the control module operates

The SMART SYSTEM control module receives inputs from boiler sensors and external devices. The control module activates and controls the blower and gas valve to regulate heat input and switches the boiler, Domestic Hot Water (DHW), and system pumps on and off as needed. The user programs the module to meet system needs by adjusting control parameters. These parameters set operating temperatures and boiler operating modes. Boiler operation can be based on boiler outlet water temperature, boiler inlet water temperature, system temperature, a 0 - 10V signal, or Modbus, depending on the parameter settings.

Control inputs and outputs

Room thermostat

There are three (3) thermostat connections available on this control. These inputs tell the boiler to provide water for space heating. Each thermostat connection has its own set point and outdoor air reset curve. When multiple thermostats have a call for heat the control will give priority to the demand with the highest set point.

Example: Assume that both Room Thermostat 1 and Room Thermostat 2 have a call for heat. RoomThermostat 1 has a set point of 110°F. Room Thermostat 2 has a set point of 140°F. The boiler will regulate the system temperature to 140°F until Room Thermostat 2 has been satisfied. Once Room Thermostat 2 has been satisified the boiler will provide 110°F water to the system.

￿CAUTION When multiple temperature loops are used, thermostatic mixing valves are

required for the protection of any low temperature loops.

0 - 10V input (set point or power)

The Knight XL can be controlled by a Building Management System (BMS) using a 0 - 10 VDC signal. The control can be configured by the installer to use this signal to either control set point or firing rate.

The Knight XL can also be programmed to accept a call for heat from a 0 - 10V signal, reference the Knight XL Service Manual for a detailed explanation of this procedure.

Installation & Operation Manual

DHW priority

The SMART SYSTEM control allows the connection of a DHW thermostat or tank sensor to the low voltage connection board. When a tank sensor is connected, the DHW thermostat input is ignored.

DHW / space heating (SH) cycling

If a DHW call for heat is received while a space heating call is in progress and the DHW is in Normal Mode, the control will start the DHW pump and shut the boiler pump off. The system pump will remain on. If the space heating call is still active while the DHW call is in operation, the control will wait for 30 minutes (time adjustable by installer) then it will switch back to the space heating demand. There is a timer to switch from space heating to DHW and a timer to switch from DHW to space heating. The control will switch back and forth until one of the heat demands end. This function does not apply to cascade systems.

Programmable controlling sensor

The control module is programmed to use the outlet sensor as the control sensor by default. If a system supply sensor is connected, the control automatically uses it as the control sensor. The control sensor can be changed by the installer to the inlet sensor. If the inlet sensor is chosen as the controlling sensor, it is recommended that the system supply sensor be installed in the system supply in order to provide the best control of the inlet temperature.

Anti-cycling

After the burner turns off, the control will delay the next burner cycle for a set time period (time is adjustable by the installer). The time delay will be bypassed if the inlet water temperature drops too far during the delay.

Boiler and system pump control

The boiler pump will run whenever the burner is firing, unless the DHW is programmed for Normal Mode and the boiler is heating the DHW tank. The boiler pump will run during Freeze Protection Mode as well. It will continue to run for a short time after the burner turns off or the Freeze Protection Mode ends.

The system pump will run whenever there is a space heating call for heat, or the boiler goes into Freeze Protection Mode. It will continue to run for a short time after the end of the heat demand or the Freeze Protection Mode. The system pump can be programmed to run continuously if desired. In either case, it will not run during outdoor shutdown.

Temperature control

Modulation

The Knight XL is capable of modulating its firing rate from a minimum of 20% to a maximum of 100%. The firing rate is dictated by the call for heat (i.e., space heating or domestic hot water), the heating load, ramp delay (if enabled), and various other temperature limitations.

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Lochinvar 400, 801 operation manual Operating information, General
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400, 801 specifications

The Lochinvar 801,400 is a cutting-edge solution in the realm of high-efficiency commercial water heating. This model represents a significant advancement in the design and functionality of water heaters, catering primarily to the demands of large-scale facilities like hotels, hospitals, and large industrial operations.

One of the standout features of the Lochinvar 801,400 is its impressive heating capacity, which can produce up to 801,400 BTUs, making it suitable for high-demand applications. This output is crucial for establishments that require a consistent supply of hot water, such as commercial kitchens and laundry facilities. The robust design ensures that it can handle peak demand periods without compromising performance.

Another significant aspect is the innovative use of advanced technology in its operation. The Lochinvar 801,400 integrates smart controls that enhance its efficiency and ease of operation. These controls allow for precise monitoring and adjustment of water temperatures, ensuring that the system operates within optimal parameters while maximizing energy savings. The intelligent monitoring system can provide real-time updates, making it easier for facility managers to keep track of performance and address maintenance needs proactively.

The construction of the Lochinvar 801,400 incorporates durable materials that not only enhance the longevity of the unit but also offer resistance to corrosion and wear. This durability translates into lower maintenance costs and an extended lifespan for the unit, making it a worthwhile investment for businesses.

Moreover, the Lochinvar 801,400 is designed with energy efficiency in mind. It boasts a high thermal efficiency rating, which reduces operational costs and minimizes the carbon footprint of heating operations. This efficiency is critical in today’s environmentally conscious market, where businesses are seeking to reduce their energy consumption and comply with strict regulations.

The design of the Lochinvar 801,400 also prioritizes safety, featuring innovative safety controls and fail-safes that protect both the unit and the users.

In summary, the Lochinvar 801,400 offers a combination of high capacity, advanced technology, durability, and energy efficiency, making it an excellent choice for commercial water heating solutions. As industries continue to evolve, the demand for reliable and efficient water heating solutions like the Lochinvar 801,400 will only increase.
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