312A

Table 14 – 2-Stage Furnace Blower OFF delay Setup Switch

DESIRED HEATING MODE

SETUP SWITCH

SETUP SWITCH

BLOWER OFF DELAY (SEC.)

SW---2

SW---3

90

OFF

OFF

120

OFF

ON

150

ON

OFF

180

ON

ON

THERMOSTAT SUBBASE TERMINALS WITH THERMOSTAT REMOVED (ANITICIPATOR, CLOCK, ETC.,

MUST BE OUT OF CIRCUIT.)

HOOK-AROUND AMMETER

R Y W G

10 TURNS

FROM UNIT 24-V CONTROL TERMINALS

EXAMPLE:

5.0 AMPS ON AMMETER

=

0.5 AMPS FOR THERMOSTAT

10 TURNS AROUND JAWS

ANTICIPATOR SETTING

 

 

A96316

Fig. 56 - Amp. Draw Check with Ammeter

Step 4 — Check Safety Controls

The flame sensor, gas valve, and pressure switch were all checked in the Start-up procedure section as part of normal operation.

1.Check Main Limit Switch(es)

This control shuts off combustion system and energizes air-circulating blower motor, if furnace overheats. By using this method to check limit control, it can be established that limit is functioning properly and will operate if there is a restricted return-air supply or motor failure. If limit control does not function during this test, cause must be determined and corrected.

a.Run furnace for at least 5 minutes.

b.Gradually block off return air with a piece of cardboard or sheet metal until the limit trips.

c.Unblock return air to permit normal circulation.

d.Burners will re-light when furnace cools down.

2.Check draft safeguard switch.

The purpose of this control is to cause the safe shutdown of the furnace during certain blocked vent conditions.

a.Verify vent pipe is cool to the touch.

b.Disconnect power to furnace and remove vent connector from furnace vent elbow.

c.Restore power to furnace and set room thermostat above room temperature.

d.After normal start-up, allow furnace to operate for 2 minutes, then block vent elbow in furnace 80% of vent area with a piece of flat sheet metal.

e.Furnace should cycle off within 2 minutes. If gas does not shut off within 2 minutes, determine reason draft

safeguard switch did not function properly and correct condition.

f.Remove blockage from furnace vent elbow.

g.Switch will auto-reset when it cools.

h.Re-install vent connector.

NOTE: Should switch remain open longer than 3 minutes, furnace control board will lockout the furnace for 3 hours. To reset furnace control board, turn thermostat below room temperature or from HEAT to OFF and turn 115-v power OFF, then back ON.

3.Check Pressure Switch(es)

This control proves operation of the draft inducer blower.

a.Turn off 115-v power to furnace.

b.Disconnect inducer motor lead wires from wire harness.

c.Turn on 115-v power to furnace.

d.Set thermostat to “call for heat” and wait 1 minute. When pressure switch is functioning properly, hot surface igniter should NOT glow and control diagnostic light flashes a status code 32. If hot surface igniter glows when inducer motor is disconnected, shut down furnace immediately.

e.Determine reason pressure switch did not function properly and correct condition.

f.Turn off 115-v power to furnace.

g.Reconnect inducer motor wires, replace outer door, and turn on 115-v power.

h.Blower will run for 90 seconds before beginning the call for heat again.

i.Furnace should ignite normally.

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Bryant 120 instruction manual Check Safety Controls, Stage Furnace Blower OFF delay Setup Switch
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120 specifications

The Bryant 120 is a remarkable system designed for residential and commercial heating and cooling needs, showcasing an impressive blend of efficiency, reliability, and advanced technology. As a part of Bryant's extensive line of HVAC solutions, the Bryant 120 stands out with its features and performance, making it an ideal choice for those seeking comfort year-round.

One of the main features of the Bryant 120 is its exceptional energy efficiency. It boasts a high Seasonal Energy Efficiency Ratio (SEER) rating, enabling homeowners to save on energy costs while enjoying consistent temperature control. This efficiency is aided by its variable-speed compressor, which allows the system to adjust its output based on current requirements, optimizing both energy consumption and comfort.

In terms of technology, the Bryant 120 incorporates advanced controls that enhance user experience and system performance. The system comes equipped with smart thermostats that allow homeowners to monitor and adjust their environment remotely. These thermostats not only provide convenience but also help in optimizing energy usage by learning the household's heating and cooling patterns.

Another characteristic of the Bryant 120 is its durable construction. The unit is built to withstand various weather conditions, featuring a robust cabinet and components designed for longevity. This durability ensures that homeowners can rely on the system for years without the need for frequent repairs or replacements.

Noise levels are also a critical consideration in HVAC systems, and the Bryant 120 addresses this with its quiet operation. The system is designed to minimize sound output, making it suitable for residential areas where noise can be a concern. This is particularly beneficial for nighttime use, providing a comfortable sleeping environment.

Additionally, the Bryant 120 supports eco-friendly refrigerants that comply with environmental standards, contributing to a reduction in greenhouse gas emissions. This commitment to sustainability reflects Bryant's dedication to creating products that are not only effective but also responsible.

Overall, the Bryant 120 encapsulates a harmonious balance of efficiency, advanced technology, durability, and quiet operation. Whether for a new installation or a replacement, the Bryant 120 presents an ideal solution to meet diverse heating and cooling requirements, enhancing comfort while prioritizing energy savings and environmental responsibility.
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