Bradford White BWCH Operations Instructions download pdf (Page 46)

Page 46

BRADFORD WHITE CORP.

The control then operates the boiler stages to maintain

the programmed boiler target temperature. The reset

override operation is not affected by WWSD.

6.4.10 External Boiler Operation

When mode 6 is selected, the control allows for

an external control to operate the Copper Brute II’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 Copper Brute II for heat. The

Copper Brute II 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 signal to these terminals. The control

energizes the boiler pump (if equipped), energizes

the Pmp-Pmp terminals, and turns on the boiler pump

segment in the display. The control also turns on

stage 1 of the boiler. Section 5.3 contains important

information about external staging controls and

building automation systems. Other wiring methods

may be unsafe. The wiring in Section 5.3 of this

manual must be used.

6.4.11 Limit Controls

In addition to the temperature control, Copper

Brute II appliances are tted with a manual reset

high limit and an automatic reset high limit. These

are located near the rear of the cabinet on the right

side, behind the slide out drawer (see Figure 32).

Both controls should be set at least 25°F higher than

the target temperature to avoid short cycling. To set

these controls, remove the control panel cover and

pull the control panel out to gain access. Appliances

with reversed heat exchangers have the limit controls

relocated to the left side of the appliance. The left

access door must be removed to gain access to the

limit controls on these appliances.

6.4.12 Advanced Programming Mode

Advanced programming mode allows the

installer to set the temperature control for proportional

staging. In advanced programming mode, the

interstage differential, interstage delay, interstage on

and off delay, and minimum time on and off are all set

manually.

NOTE: Advanced programming mode is rarely

required. It is intended for advanced installers,

and only when the application demands such

programming.

To enter advanced programming mode, remove

the bezel on the temperature control by pulling out at

the bottom. Remove the small phillips head screw to

access the dip switch. The dip switch is mounted on a

circuit board.

Locate the letter “A” on the circuit board and

slide the corresponding dip switch toward the letter

“A”. The default setting of this dip switch is toward

the

OFF lettering on the circuit board.

6.5 Operating the Burner and Set Up

6.5.1 Set Up for 0 to 2500 Feet Altitude

The Copper Brute II appliance utilizes a modular

design to achieve its stage-ring. The setup must be

checked before the unit is put in operation. Problems

such as failure to start, rough ignition, strong exhaust

odors, etc. can be due to improper setup. Damage to

the Copper Brute II resulting from improper setup is

not covered by the limited warranty.

1. Using this manual, make sure the installation

is complete and fully in compliance with the

instructions.

2. Determine that the appliance and system are

lled with water and all air has been bled from

both. Open all valves.

3. Observe all warnings on the Operating

Instructions label and turn on gas and electrical

power to appliance.

4. Switch on the appliance power switch located on

the right side of the unit.

5. The Copper Brute II will enter the start sequence,

as long as the unit is being called for heat. The

blower and pump come on for pre-purge, then

the ignitor warm-up sequence starts and after

the ignitor warm-up is complete and all safety

devices are veried, the gas valves open. If

ignition doesn’t occur, check that there is proper

gas supply. Wait 5 minutes and start the unit

again. During initial start up, air in the gas line

may cause the Copper Brute II to "lock out"

during the rst few trials for ignition. Depending

on the ignition modules installed, the manual

reset button on the ignition modules may need to

be depressed to restart the Copper Brute II.

6. When the unit is running, the supply gas pressure

must be checked. Inlet gas pressure must not

exceed 13" w.c. (3.2kPa). The minimum inlet gas

pressure is 5" w.c. (1.2kPa).

7. Once the inlet gas pressure is veried, the

outlet gas pressure from each valve (manifold

gas pressure) must be checked, and adjusted, if

necessary. The manifold gas pressure must be

2.5" w.c. (0.62kPa).

8. Complete the setup by checking the CO

at the

outlet of the unit. The CO

should be 8% for

natural gas, or 9.2% for propane.

9. After placing the appliance in operation, the

Burner Safety Shutoff Device must be tested.

To test:

(a) Close gas shutoff valve with burner

operating.

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