Bradford-White Corp BWCV Manual De Usuario

Internet Version for Reference Only

Page 28

Copper Brute II

Page 29

The heater target temperature is set using the 

BOIL TARGET item in the Adjust menu. 

Note: External demand is not required in this 

mode of operation.

Tank Differential – A differential setting that 

operates 1⁄2 above and below the TANK TARGET is 

selectable using the TANK DIFF item in the Adjust 

menu.

When either mode 4 or 5 is selected, the control 

uses outdoor reset to control the water temperature. 

Outdoor reset adjusts the target temperature based 

on the outdoor air temperature and reset ratio. The 

reset ratio is determined from the Boiler Start, Boiler 

Design, Outdoor Start and Outdoor Design settings.

Heat Demand – For “heat demand” to exist, 

there must be continuity between the Com D (common 

demand) and the Ht D (heat demand) terminals. The 

heater ships with a jumper between these terminals. 

The control also evaluates the sensor(s) installed 

in the system. If the control is not in warm weather 

shutdown (WWSD), and the sensor(s) are below the 

target temperature, the Dem segment is turned on 

in the display. The control energizes the pump (on 

pump mounted boilers) and energizes the Pmp-Pmp 

terminals, and the heater pump segment is turned on 

in the display. The control then operates the stages to 

maintain the set point temperature.

Boiler Start (BOIL START) – The BOIL 

START temperature is the theoretical boiler supply 

water temperature that the heating system requires 

when the outdoor air temperature equals the OUTDR 

START temperature setting. The BOIL START is 

typically set to the desired building temperature (see 

Figure 15). 

Outdoor Start (OUTDR START) – The 

OUTDR START temperature is the outdoor air 

temperature at which the control provides the BOIL 

START water temperature to the system. The OUTDR 

START is typically set to the desired building 

temperature.

Outdoor Design (OUTDR DSGN) – The 

OUTDR DSGN is the outdoor air temperature that is 

the typical coldest temperature of the year where the 

building is located. This temperature is used when 

doing heat loss calculations for the building.

Boiler Design (BOIL DSGN) – The BOIL 

DSGN temperature is the water temperature required 

to heat the boiler zones when the outdoor air is as cold 

as the OUTDR DSGN temperature.

Warm Weather Shut Down (WWSD) – When 

the outdoor air temperature rises above the WWSD 

setting, the control turns on the WWSD segment 

in the display. When the control is in WWSD, the 

Dem segment is displayed if there is a heat demand. 

However, the control does not operate the heating 

system to satisfy this demand. The control does 

respond to a set point demand and operates as 

described in the Reset Override section (next).

– This is used when override of the outdoor reset curve 

is needed, such as when an indirect water heater is 

served by the heating system. A set point demand is 

required whenever heat is required for the set point 

load. The set point demand overrides the reset water 

temperature. The control turns on the Setp Dem 

pointer in the display. The control energizes the pump 

(on pump-mounted heaters), energizes the Pmp-Pmp 

terminals, and turns on the heater pump segment in the 

display. The control then operates the heater stages to 

maintain the programmed target temperature. The reset 

override operation is not affected by WWSD.

When mode 6 is selected, the control allows for 

an external control to operate the heater’s stages. In 

this mode, the control operates the pump in order to 

provide purging and exercising. The staging operation 

is provided by an external device such as an Energy 

Management System (EMS) or External Staging 

Control.

Heat Demand – A heat demand is generated 

when stage one is wired properly, and the external 

control closes the contacts on the stage one terminals 

(1C-1NO), calling the heater for heat. The heater is 

shipped with a jumper between the Com D and Ht D 

terminals, and this jumper must remain in place when 

and external control is providing the heat demand