Outdoor reset operation, if used, Cascade

Installation & Operation Manual

11 Operating information

Low water cutoff protection

1.The SMART SYSTEM control module uses temperature sensing of both supply and return areas of the heat exchanger. If the ﬂow rate is too low or the outlet temperature too high, the control module modulates and shuts the boiler down. This ensures boiler shutdown in the event of low water or low ﬂow conditions.

2.Some codes and jurisdiction may accept these integral features of the control in lieu of requiring an additional limit control or low water cutoff. Consult local jurisdiction to determine. A low water cutoff is available from the factory (WTR20009).

Outdoor reset operation, if used

Target temperature with outdoor reset

This feature improves the system’s efﬁciency as the outdoor temperature warms up.

See the Knight XL Service Manual to change the settings.

Reset curve

The reset curves look at outdoor air temperature and adjusts the set points.

Cascade

When multiple boilers are installed, they can be wired together in a cascade sequence. A maximum of eight boilers can be controlled from a single control. In this application one boiler would be designated as the Leader control and all others would be designated as Member controls. If installing the boilers in an existing system, the new boilers should be programmed as the Leader and/or the higher number addresses. The Leader control can be programmed to use Lead/Lag or Efﬁciency Optimization control methods.

Once the Leader boiler receives a call for heat from a room thermostat, BMS, or Modbus, the control will determine what the set point will be. If outdoor air reset is desired, connect the outdoor air sensor to the terminals on the Low Voltage Connection Board on the Leader boiler. The set point will be calculated based on the programmed reset curve parameters. See the Knight XL Service Manual to program the reset curve. If outdoor air reset is not desired, do not connect the outdoor air sensor. A ﬁxed temperature set point can be programmed into the control. See page 59 of this manual to program the set point.

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.

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:

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

If a boiler is used to heat an indirect DHW tank, it will automatically be given the lowest priority.

DHW, Night Setback, and Ramp Delay operation with cascade

For normal mode 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 or sensor to the terminals on the Low Voltage Connection Board marked for the corresponding device. 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 in Cascade Mode.

When DHW is programmed for Zone Mode, connect the DHW thermostat or tank sensor to the Leader boiler. When a DHW call is received, the Leader will modulate the entire Cascade to bring the system supply temperature up to the DHW boiler set point (if higher).

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 available when the boilers are part of a Cascade system.

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.

Lochinvar 801, 400 operation manual Outdoor reset operation, if used, Cascade

Models: 400 801