Lochinvar 400 - 801 service manual Anti-Cycling

Service Manual

1Service (continued)

Outdoor Air Shutdown Differential (SH1 - SH3)

The outdoor air shutdown differential parameter is the number of degrees below parameters F5, F10 and F15 the outdoor air temperature must go before the boiler will respond to a SH demand. These parameters can be changed by the installer by accessing parameters F6, F11 and F16. The temperature range of this parameter is 0°F (0°C) to 90°F (50°C). The default value is 10°F (6°C).

Shift Reset Curve (SH1 - SH3)

There is a shift reset curve for each outdoor reset. The shift reset curve parameter shifts the actual set point above the calculated set point the number of degrees in this parameter. These parameters can be changed by the installer by accessing parameter F7, F12 and F17. The temperature range of this parameter is -17°F (-27°C) to 18°F (-8°C). The default value is 0°F (0°C). This feature will be active if this parameter is set to anything other than 0°F (0°C).

Boost Temperature

If a SH demand lasts longer than the programmed time delay setting (F19) and there have been no DHW demands, the control will increase the water temperature set point by the amount in this parameter. If the SH demand continues through another time period, the set point will be increased again. This will continue until either the SH demand ends, a maximum of 20 increases has occurred, or the maximum set point has been reached. Once the SH demand has been satisfied the set point will revert back to its calculated setting. The boost temperature can be changed by the installer by accessing parameter F18. The temperature range of this parameter is 0°F (0°C) to 25°F (-4°C). The default value is 0°F (0°C). This feature will be active if this parameter is set to anything other than 0°F (0°C).

Boost Time

The boost time parameter sets the amount of time that must elapse with a SH demand before the water temperature set point will be increased. This parameter can be changed by the installer by accessing parameter F19. The time range for this parameter is 0 minute to 50 minutes. The default value is 0 minutes.

G: Anti-Cycling

Anti-Cycling Time

Once a SH demand has been satisfied, a set amount of time must elapse before the control will respond to a new SH demand. The control will block the new heat demand and anti-cycling will be shown in the display until the time has elapsed or the water temperature drops below parameter G2. This parameter can be changed by the installer by accessing parameter G1. The time range for this parameter is 0 minutes to 10 minutes. The default value is 1 minute.

Anti-Cycling Override Differential

The control will bypass the anti-cycling time if the water temperature drops too quickly. The control will use the water temperature the boiler was at when it shut off as the starting point. If the temperature drops below the temperature parameter the control will abort anti-cycling and allow the boiler to fire. This parameter can be changed by the installer by accessing parameter G2. The temperature range of this parameter is 0°F (0°C) to 54°F (30°C). The default value is 10°F (6°C).

Ramp Delay (Enable / Disable)

This parameter allows the installer to enable or disable the SH ramp delay by accessing parameter G4.

23