1Service

F: Control modes

BMS Thermostat Input (Active / Inactive)

When controlling the water heater through the 0 - 10V BMS input or through ModBus, the water heater can be enabled one of two ways. With parameter F1 set to ACTIVE, the water heater will be enabled by closing the Tank Thermostat input. With parameter F1 set to INACTIVE, the water heater 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.

BMS (Active / Inactive)

The set point or modulation of the water heater may be controlled through the 0 - 10V BMS input or through ModBus. When parameter F2 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 (Active / Inactive)

When BMS is set to ACTIVE (see BMS Active / Inactive) and the water heater is being controlled through ModBus, set parameter F3 to ACTIVE. Otherwise, set the ModBus parameter to INACTIVE. Note that the water heater can still be monitored by ModBus with this parameter set to INACTIVE. The default value is INACTIVE.

ModBus T/O (Timeout)

The ModBus T/O is 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 is used to prevent unwanted operation should ModBus communication be lost. Therefore, the ModBus commands need to be refreshed within this time period. This parameter is adjustable by the installer by accessing parameter F4. The default value is 10 seconds.

Service Manual

Cascade Address

The water heater designated as the Leader needs to be programmed with address 0. All the Member water heaters 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 F5. The tank sensor must be connected to the Leader water heater. The default address is 1.

If installing the water heaters in an existing system with existing Armor water heaters with old style controls, the new water heaters 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 at L/L in the menu. This method will modulate the last two

(2)water heaters only. When the last water heater reaches 100% and the calculated load is still increasing, it will start the next water heater at 20% and reduce the previous water heater to 80%. When the calculated load is decreasing and the last water heater gets down to 20% fire, it will hold it there and start lowering the firing rate on the next-to-last water heater. When the next-to-last water heater reaches 20%, it will turn the last water heater off and raise the rate of the next-to-last water heater to 40%, thus eliminating the sudden drop in total output of the Cascade.

The other Cascade divider method is Efficiency Optimization, designated as EFF in the menu. This method is used, as the name implies, when it is desired to have the most efficient system. When the first water heater reaches a certain rate (default = 90%), it lowers its rate to 45% and turns on the next water heater at 45%. The two (2) water heaters then modulate at the same rate.

As the calculated load increases further and both water heaters ramp up to 90%, it lowers the rate of the first two

(2)water heaters to 60% and brings the next water heater on at 60%. The three (3) water heaters then modulate together. As the calculated load decreases, the water heaters will reach a lower threshold (default = 30%), at which time the last water heater (the third in our example) will turn off and the Cascade will increase the rates of the remaining water heaters to provide the equivalent total output as before ((3 x 30%) / 2 = 45% in our example).

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Lochinvar 151 - 801 service manual Control modes
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151 - 801 specifications

Lochinvar 151 - 801 is a high-efficiency commercial water heater designed to meet the demanding needs of various applications in the hospitality, healthcare, and educational sectors. This advanced system provides reliable hot water with enhanced performance while promoting energy conservation and sustainability.

One of the standout features of the Lochinvar 151 - 801 is its powerful heating capability. With a robust heating input of up to 150,000 BTU per hour, it ensures a steady supply of hot water even during peak demand times. The efficient heat exchanger design optimizes thermal performance, allowing for quicker recovery rates, which is essential for facilities requiring substantial hot water usage.

This model integrates cutting-edge technologies to maximize energy efficiency. Utilized in the Lochinvar 151 - 801 is the Smart System control technology, which provides precise temperature management and diagnostics. This feature not only enhances operation efficiency but simplifies service and maintenance by providing real-time data and alerts, leading to reduced downtime.

Additionally, the Lochinvar 151 - 801 employs a stainless-steel tank construction that promotes durability and robustness. The tank is adequately insulated to minimize heat loss, thus keeping energy costs down. Its compact design also allows for easy installation in various spaces, including those with limited footprints.

Moreover, the unit features advanced combustion technology, including a modulating gas valve that adjusts the flame size according to demand, promoting even greater efficiency. This ensures that the water heater operates at optimum performance levels, reducing fuel consumption while ensuring a consistent supply of hot water.

Safety is a primary concern for Lochinvar, and the 151 - 801 model includes several integrated safety features, such as an ignition safety shutoff and a temperature/pressure relief valve. These systems work together to provide peace of mind while ensuring the unit operates safely within its designated parameters.

In conclusion, the Lochinvar 151 - 801 is an exemplary choice for commercial applications, offering powerful performance, efficient technologies, durable construction, and enhanced safety features. With its combination of high output and advanced monitoring capabilities, it stands as a reliable solution for organizations seeking an effective hot water heating solution.
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