Installation & Operation Manual

8Field wiring

System supply sensor

1.By installing the system supply sensor into the supply of the primary loop, the temperature of the primary supply can be controlled. The SMART SYSTEM control automatically detects the presence of this sensor, and controls the boiler firing rate to maintain the system supply temperature to the set point (if the outlet sensor control is currently selected). If it is desired to control the system return temperature, then program the SMART SYSTEM control to use the inlet sensor as the controlling sensor. See the Knight Wall Mount Service Manual for instructions on how to do this. When the inlet sensor is programmed as the controlling sensor, it is strongly recommended that the SYSTEM SUPPLY sensor be installed. DO NOT INSTALL THE SYSTEM SUPPLY SENSOR INTO THE SYSTEM RETURN.

2.The TST2032 sensor provided with the boiler must be used for the system sensor.

3.Connect these terminals to the system supply sensor (FIG. 8-4).

Boiler management system

1.An external control may be connected to control either the firing rate or the set point of the boiler. If the external control uses a set of contacts to enable the boiler, connect the contacts to the Room Thermostat 1 terminals. Otherwise, the SMART SYSTEM control will be enabled by the 0-10V signal.

2.Make sure the ground terminal is connected to the ground output terminal of the external control, and the 0 - 10 vdc terminal is connected to the 0 - 10 vdc terminal of the external control.

Runtime contacts

The SMART SYSTEM control closes a set of dry contacts whenever the burner is running. This is typically used by Building Management Systems to verify that the boiler is responding to a call for heat.

Alarm contacts

The SMART SYSTEM control closes another set of contacts whenever the boiler is locked out or the power is turned off. This can be used to turn on an alarm, or signal a Building Management System that the boiler is down.

Wiring of the cascade

When wiring the boilers for Cascade operation, select one boiler as the Leader boiler. The remaining boilers will be designated as Members. See page 60 “Configuration of the Cascade” for a detailed explanation of this procedure.

Connect the system supply sensor and outdoor air sensor (if used) to the Leader boiler. For the Cascade system to work properly the system supply sensor must be installed. The location of the system supply sensor should be downstream of the boiler connections in the main system loop (FIG.’s 6-4 and 6-6). The system supply sensor should be wired to the Low Voltage Connection Board at the terminals marked for the system sensor (see FIG. 8-4). The Leader control will use the water temperature at the system supply sensor to control the operation of the Cascade.

If outdoor air reset is desired, the outdoor air sensor should be wired to the Low Voltage Connection Board at the terminals marked for the outdoor air sensor (FIG. 8-4). If the outdoor air sensor is connected, the Leader control will calculate the water temperature set point based on the programmed reset curve parameters. If the outdoor air sensor is not connected, the Leader control will maintain the fixed water temperature set point that is programmed into the control.

If a Thermostat, Zone Control enable output, or Building Management System enable output is available, it should be wired to the Low Voltage Connection Board on the Leader boiler at the terminals marked for one of the Room Thermostats 1-3 (FIG. 8-4). If the boilers are to run continuously, connect a jumper wire between the R and W terminals for the Thermostat input. This will initiate a call for heat on the Cascade.

Communication between the Leader boiler and the Member boilers is accomplished by using shielded, 2-wire twisted pair communication cable. Connect one of the twisted pair wires to Cascade terminal A on each of the Low Voltage Connection boards, and the other wire of the twisted pair to Cascade terminal B on each of the Low Voltage Connection Boards. Connect the shield wires to one of the shield terminals on the Low Voltage Connection Boards (FIG. 8-4). If more than two boilers are on the Cascade, daisy chain the wiring from the Cascade terminals on the second boiler to the Cascade terminals on the third boiler, then from the third to the forth, and so on. The connections between boilers can be made in any order, regardless of the addresses of the boilers. Try to keep each cable as short as possible.

52

Page 51 Page 53
Page 52
Image 52
Lochinvar 51 System supply sensor, Boiler management system, Runtime contacts, Alarm contacts, Wiring of the cascade
Page 51 Page 53

51 specifications

Lochinvar 51 is an innovative and robust residential boiler system designed for high-efficiency heating needs. A popular choice among homeowners, the Lochinvar 51 stands out in the market due to its advanced features and eco-friendly technologies.

One of the main features of Lochinvar 51 is its compact design, making it ideal for installation in limited space environments such as attics or closets. Despite its small footprint, it boasts a powerful heating capacity, suitable for varying home sizes. The boiler operates with a modulating gas burner that allows it to adjust its heat output according to the demand, ensuring efficiency and comfort throughout the day.

The Lochinvar 51 employs a cutting-edge heat exchanger made from stainless steel, which is highly durable and resistant to corrosion. This design not only enhances the boiler's performance but also increases its lifespan. The unit offers impressive AFUE (Annual Fuel Utilization Efficiency) ratings, showcasing its capability to convert a significant portion of fuel into usable heat, thus minimizing energy waste and reducing heating costs.

Technologically, the Lochinvar 51 is equipped with advanced control systems that facilitate precise temperature management. The intuitive interface allows homeowners to easily set their desired temperature and monitor the system’s performance. Additionally, the integration of outdoor reset technology helps optimize energy consumption by adjusting the water temperature based on outside weather conditions, leading to further energy savings.

Safety features are also paramount in the Lochinvar 51. It includes built-in safeguards that monitor pressure and temperature, automatically shutting down the system in case of any irregularities. This not only protects the boiler but also ensures peace of mind for users.

Moreover, Lochinvar 51 supports compatibility with smart home systems, providing homeowners with remote control capabilities via mobile devices. This innovative feature enhances user convenience, allowing for easy adjustments and monitoring of the heating system from anywhere.

In conclusion, the Lochinvar 51 is an exceptional choice for homeowners looking for a reliable, efficient, and technologically advanced heating solution. With its impressive heating capacity, durable design, and innovative control features, it sets a high standard in residential boiler performance, making it a top contender in today’s market.
Top Page Image Contents