Domestic Hot Water DHW Priority, Setback, Boost

Setback:

BCP-3 Installation and Operation Manual

Domestic Hot Water (DHW) Priority		DHW	Priority:
Options: NO and From 1 min to 120 min	Default: NO	60m

SET /Settings>/DHW Prior.

•The DHW Priority, with a value set to other than NO, provides the user with an adjustable DHW priority timer for the domestic hot water call. That is, initiating a DHW call will de-energize the system pump relay for the period set by the DHW Priority. However, the DHW relay, when 1-On/Off+2-Pump is selected as the Output mode from the Startup menu, will remain energized for as long as the DHW is active. This will take place whenever the Outdoor temperature is below Outdoor Cutoff and the EXT+/ EXT- (Enable/Disable terminals) are closed/shorted.

•On the other hand, when the EXT+/EXT- (Enable/Disable terminals) are open or the Outdoor temperature is 2°F above the Outdoor Cutoff, a DHW priority call will energize the DHW pump and boiler relays. When the DHW call expires, the DHW Pump relay will remain energized for the Run-On delay then de-energize.

•If NO was selected as the option for the DHW Priority, a DHW call will energize both relays, system pump and DHW pump even when TSTAT is de-activated.

Setback

Options: From 0ºF/0ºC to 80ºF/44ºC	Default: 10ºF/6ºC	20 F
SET /Settings>/Setback.		SYSTEM=	68	F
• The Setback feature can be used to provide the BCP-3 with a lower temperature Set Point when		SYSTEM=	68	F
		SBC TGT=	140	F
less heat is required by closing the P+ and P- terminals.		SBC TGT=	140	F
less heat is required by closing the P+ and P- terminals.
• The lower Set Point will appear on the main display indicating SBC	TGT= .

•For example; when the calculated temperature is 160°F and the Setback is set to 20°F, a setback call will change the Set Point to (160°F - 20°F) 140°F.

•A typical use for the Setback is to provide a reduced system temperature to a building during the night or on the weekends when building is not occupied, but heat is still required.

•The Setback is activated by closing/shorting the P+ and P- terminals using an external timer, control, or a switch.

Boost

Options: Yes, No

Default: No

SET /Settings>/Setback/Boost.

•The morning Boost is designed to return the building to comfortable ambient temperatures after the night Setback period. The BCP-3 will accomplish this by running elevated water temperatures (will add Setback setting to calculated water temperature) for 30 minutes after the opening of the setback terminals P+ and P-. That is, if the normal set point at a speciﬁc outdoor was 145˚F and the Setback setting was 20˚F, the boost will raise the system calculated temperature to 165˚F for 30 minutes after the setback.

Boost:

Yes

System and Outdoor Trim

Options: From -20Fº/-11Cºto +20Fº/+11Cº	Default: 0Fº/0Cº
SET /<Maintenance>/Sys. Trm or Out. Trim

•The Weil McLain sensors are very accurate. However, sometime it might be beneﬁcial to adjust the values to match and existing system. The System and Outdoor Trim values adjust the System Sensor and Outdoor Sensor readings using positive or negative values.

System Trim:

+0F

Outdoor Trim: +0F

Enable/Disable (TSTAT) Input

•The BCP-3 will provide heat only if the EXT- and EXT+ terminals are shorted. If no external equipment or switch is connected to these terminals, leave the factory jumper installed.

• When the terminals are OPEN, the Target will display TSTAT OPEN.

•Even if the EXT terminals are open, a call for DHW will energize the output relays based on the DHW Priority configuration.

•The Enable /Disable terminals can be used as a Summer/Winter switch when connected to an external switch.

NOTE: On a sensor fault while the Enable/Disable terminals are open, the control will follow the Enable /Disable state regardless of the sensor fault condition.

Enable/Disable

Wiring

COM T3+ T3- EXT+ EXT- P+ P- COM 24

SYSTEM= 55F

TSTAT OPEN

SYSTEM= SHORT

TSTAT OPEN