Lochinvar 3.5, 2.5 service manual Protection features

Page 47

Installation & Operation Manual

10 Operating information (continued)

Gradient limiting

If during operation of the boiler the outlet water temperature is rising too quickly, the control will reduce the firing rate to its lowest setting.

Outdoor air reset

If an outdoor air sensor is connected, the control module will calculate the set point based on the programmed reset curve. The installer can change the slope of the reset curve by several adjustable parameters. The user can limit the maximum set point for the system using the space heating set point.

Boost function

If outdoor air reset is active, the boost temperature is not 0, a space heating demand has been active continuously for a set period of time (time adjustable by installer) and there has been no HWG demands, the control will increase the set point by a fixed number of degrees (adjustable by installer). This process will continue until the space heating demand ends, the set point reaches the programmed set point or a maximum of 20 increases has occurred. Once the system heat demand is satisfied, the set point will revert to the value determined by the reset curve.

Night setback

The controller may be programmed to reduce the space heating set point and/or Hot Water Generator set point for each demand during a certain time each day. A start and stop time for each demand can be programmed for each day of the week. The controller can be programmed to reduce the tank set point as well. A different set of start and stop times can be programmed each day of the week.

Flame current support

To prevent nuisance shutdowns when the boiler is firing at minimum rates, the control will increase the firing rate when the flame signal drops too low.

ModBus

The Crest boiler can be connected to and controlled by a Building Automation System through the ModBus interface. Connect the A and B wires to the A and B terminals. If connecting another cable (in a daisy chain), connect the shield wire of the first cable to one of the shield terminals, and the shield wire of the second cable to the other shield terminal. If it is desired to ground the cable shield at the heater, connect the shield wire to one of the shield terminals, and install a jumper across the two (2) terminals in connector X5 on the ModBus interface board.

0-10V Rate output

A 0-10V signal which indicates the firing rate of the heater is available. This output may be connected to a Building Management System (BMS) to allow it to monitor the actual firing rate. Connect the - terminal to the COM or - terminal on the BMS, and connect the + terminal to the 0 - 10V or + terminal on the BMS.

Ramp Delay

For systems with lower flow, the SMART TOUCH can limit the firing rate (when enabled) when a space heating call for heat starts, or when switching from a DHW call for heat to a space heating call for heat. There are six (6) limits that can be programmed, as well as six (6) time intervals corresponding to each limit. The sixth limit will also limit the firing rate for the rest of the call for heat.

Protection features

Outlet temperature, flue temperature, and temperature rise limiting

The outlet water temperature is monitored by the boiler outlet temperature sensor. When the outlet temperature exceeds 185°F, the unit will reduce the fan speed. If the outlet water temperature exceeds 195°F (90°C) the control will shut the unit down until the minimum off time has expired and the outlet drops 10°F (5.5°C).

The control module monitors the flue temperature by a sensor located in the flue exhaust. If the flue temperature exceeds 350°F (176°C) the control will reduce the maximum fan speed. If the flue temperature exceeds 400°F (204°C) the control will shut the unit down. The unit will restart automatically once the flue temperature drops 50°F (27°C) and the minimum off time has expired.

The control monitors the temperature difference between the inlet and the outlet sensor. If this difference exceeds 80°F (27°C) the control will reduce the fan speed. If the temperature difference exceeds 90°F (32°C) the control will shut the unit down. The unit will restart automatically once the temperature difference has dropped below 50°F (28°C) and the minimum off time has expired.

Freeze protection

DO NOT install the boiler in a room likely to freeze.

The following integral feature of the SMART TOUCH control module provides some protection for the boiler only -- not for the system.

•The SMART TOUCH control module provides freeze-up protection as follows when the boiler water temperature drops below 45°F (7°C):

•Below 45°F (7°C), the boiler and system pumps (if enabled) operate constantly.

•Below 37°F (3°C), the boiler turns on.

•Boiler and pumps turn off if boiler water temperature rises above 43°F (6°C).

￿ CAUTION

This feature of the SMART TOUCH control

module does not eliminate the possibility

 

 

of freezing. The installation must still

 

use recognized design, installation and

 

maintenance practice to prevent freeze

 

potential for the boiler and system.

 

 

 

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Contents Save this manual for future reference Contents Please read before proceeding When servicing boilerBlowers Crest How it worksCrest How it works Models 1.5 2.0 2.5 3.0 Crest Ahri Rating RatingsBefore locating the boiler, check Installation must comply withRecommended clearances for service access Determine boiler locationPrevent combustion air contamination Provide air openings to roomFlooring and foundation Vent and air pipingAreas likely to have contaminants When using an existing vent system to install a new boilerProducts to avoid When removing a boiler from existing common vent system Remove boiler from wood pallet 7Combustion Air from Outside Single Opening Minimum Recommended Combustion AIR Supply to Equipment Room Optional room air General ventingDirect venting Air inlet pipe materials Install vent and combustion air pipingAir intake/vent connections Approved Stainless Steel Vent Manufacturers Make ModelRemoving from existing vent Common venting Prepare roof penetrations Vertical direct ventingVent/air termination vertical Determine location4Alternate Vertical Terminations with Multiple Boilers Multiple vent/air terminationsVent/air termination sidewall Sidewall direct venting2Clearance to Doors and Windows Prepare wall penetrations4Multiple Vent Terminations must also comply with Figure Room airHydronic piping 20F 40F 60F Circulator sizingModel Near boiler piping components Ball Valve Multiple Boilers Common Header Primary / Secondary Flow For all equipment and detailing required by local codes AIR Seperator Drain Port Typical System Supply Sensor Model Gas Inlet Size Connecting gas supply pipingGas connections Propane Gas Natural gasCheck inlet gas supply GAS Piping Size ChartGas Pressure Gas valve replacementLine voltage connections Field wiringInstallation must comply with Low voltage connections EnableOutdoor temperature sensor Louver proving switchSystem supply sensor Auxiliary switch 1Alarm contacts Wiring of the cascadeField WiringCondensate drain Condensate disposalFill and test water system Freeze protection when usedStart-up Check/control water chemistryInspect/check condensate lines and fittings Check for gas leaksCheck thermostat circuits Inspect condensate systemCheck system and boiler Final checks before starting the boilerStart the boiler If boiler does not start correctlyFor Your Safety Read Before Operating Gas Natural Gas Propane Valve Set space heating operationSet clock Verify HWG circulator mode Set HWG target temperatureConfiguration of the cascade General Operating informationProtection features Outdoor reset operation, if used Boiler temperature regulationCascade Sequence of operation Home Screen Crest control module2Main Menu Screen See the Crest User’s Information Manual for Instructions Maintenance Maintenance and annual startupService technician Owner maintenanceMaintenance Check boiler relief valve Flue vent system and air pipingCheck water system Check expansion tankCheck flame signal Check ignition ground wiringCheck all boiler wiring Check control settingsNiosh stated First Aid Cleaning boiler heat exchangerReview with owner Handling ceramic fiber materialsIntegrated Control Diagrams2Wiring Diagram
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3, 2, 3.5, 2.5 specifications

The Lochinvar 2, 3, 3.5, and 2.5 models are a standout lineup in the realm of commercial and residential water heating solutions. Known for their advanced technology and high efficiency, these units cater to a wide range of applications, ensuring optimal performance and reliability.

One of the key features of the Lochinvar models is their robust construction. Each unit is designed to withstand rigorous operational demands while providing excellent thermal efficiency. They are equipped with stainless steel heat exchangers, which offer superior resistance to corrosion and extend the lifespan of the equipment. This durability is essential for both commercial and residential settings where demand can vary significantly.

The Lochinvar 2, 3, 3.5, and 2.5 models utilize innovative control systems that enhance their operational efficiency and user convenience. The built-in Smart Control technology allows for easy monitoring and adjusting of system parameters, ensuring that users can maintain optimal performance with minimal effort. This feature is especially beneficial in commercial settings where large volumes of hot water are required, as it enables users to effectively manage their energy consumption.

Energy efficiency is another hallmark of the Lochinvar lineup. With high-efficiency ratings, these models help reduce energy costs significantly, making them an environmentally friendly option for heating water. The use of advanced combustion technology ensures that these units can deliver maximum heat output with minimal fuel consumption.

Additionally, the Lochinvar models are designed with safety and reliability in mind. They feature multiple safety controls and diagnostics that alert users to potential issues before they escalate, providing peace of mind. The integration of advanced venting options allows for flexible installation configurations, accommodating various building layouts and space requirements.

In summary, the Lochinvar 2, 3, 3.5, and 2.5 models define modern water heating technology with their combination of durability, efficiency, and advanced features. With their innovative design and user-friendly controls, they meet the demanding needs of both commercial and residential users, making them a top choice in the water heater market. Whether for new installations or replacements, these units deliver reliable performance and value.
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