The folllowing status information is displayed from this screen:

Status Displayed

*(True Condition)

Input

Output

ECO

Outlet temperature too high

open

- - - -

LW/CO

Water Level low

open

- - - -

Blk Flue

Flue blocked

open

- - - -

Flow

Water flowing

closed

- - - -

Low Gas

Gas pressure low

open

- - - -

Tstat

Thermostat requesting heat

closed

- - - -

Hi Limit

Outlet temp exceeds High Limit setpoint

- - - -

- - - -

Pump

Pump output activated

- - - -

On

IRI Gas Pwr

IRI output relay activated

- - - -

On

IRI Gas

IRI Gas Valve on

closed

- - - -

Pwr Vent

Power Vent running

closed

- - - -

Alarm

Alarm output activated

- - - -

On

Pwr Vent Pwr

Power Vent output relay activated

- - - -

On

 

- - - - STAGES 1 to 4 - - - -

 

 

BlwHi Prv

Blower pressure sufficient

closed

- - - -

Blw Hi

Blower High output activated

- - - -

On

BlwLo Prv

Blower pressure sufficient

closed

- - - -

Blw Lo

Blower low output activated

- - - -

On

Ignt Cur

Igniter current sufficient for ignition

- - - -

- - - -

Ignit

Igniter output is activated

- - - -

On

Gas Relay

Gas output relay activated

- - - -

On

Hi Gas

Gas pressure too high

open

- - - -

Flame

Flame detected

- - - -

- - - -

The operation of these parts is described below:

UIM Screens:

On all screens a double vertical bar appears on the right side of the display each time a key is touched to indicate that a key has been activated. On several screens an indicator ">" appears on the left side of the display to indicate the active line. The "Up/ Down" keys are used to move the indicator to the desired line and the "Select" key is pressed to select the line. Also, on most of the screens, up/down arrows appear on the right side of the screen to indicate that there are additional lines either above or below the displayed four lines.

Menu Screen:

Displayed when the user presses the "Menu" key. This screen is the selection point for the other 9 screens.

Temperature Screen:

Displays the sensed temperatures of the Outlet, Inlet, and Tank probes. Also displayed is the calculated Delta T (Outlet minus Inlet) for the system. Shorted ("Short") and disconnected ("----") probes are also displayed.

System Status Screen:

This screen is used to view the status of switch inputs and output states. An asterisk (*) is displayed next to the label when the status is "True" (the description is fulfilled). For example, if water is flowing, or detected by the flow sensor, then an "*" will appear in front of the Flow label (i.e. *Flow). Another example would be the ECO switch. If the outlet temperature is too high the display will show: *ECO.

NOTE: The LW/CO, IRI Gas Valve, Powered Vent, High Gas, and Low Gas inputs are optional inputs. Flame sensing, Igniters, and Blowers are optional on Stages 2, 3 and 4. (Except on a 4- stage system, stage 2 always has an Igniter, Blower, and Flame Sensor. Those dipswitches on stage 2 are not relevant.) One or two speed blowers can be used on any stage.

The System monitors the inputs at these times:

ECO, LW/CO, Blocked Flue, Low Gas, Hi Limit, and Hi Gas - at all times for a fault condition.

Tstat - at all times for open/closed conditions.

IRI Gas and Powered Vent - for an on condition when their respective outputs (Pump, IRI Gas Pwr, Powered Vent Power) are turned on and an off condition at all other times.

Flow - for an on condition when the pump is on (no check for off state)

High Speed Blower Prover - when the High Speed Blower is on.

Low Speed Blower Prover - when either the High or Low Speed Blowers are on.

Igniter Current - for an on condition approximately 18 seconds after the Igniter is turned on until the igniter is turned off and an off condition at all other times.

Flame - for an on condition approximately 5 seconds after the gas valve is turned on until the valve is turned off and at all other times for an off condition.

Control Status Screen:

Displays the software that the CCB and FCB micros are in. The CCB has 8 possible states and the FCB's have 9. The normal CCB states sequence is to move from Idle, to Pre-Circulate, then to Heating Stage 1-4 when a call for heat is initiated. Once heat has been satisfied or the Total is opened, the sequence moves to Post-Circulate and then back to Idle. If a fault occurs at any time, the process jumps out of sequence and goes directly to the appropriate Hard or Soft Fault state.

Description of CCB control states:

Idle:

The yellow "Standby" LED is turned on and the system waits for a heat request (determined by the Thermostat and controlling probe inputs). All outputs are off in this state except that if the Post-Circulate time is set to continuous the pump will be on. When the heat request is received, the system moves to the Pre-Circulate state.

Pre-Circulate:

The yellow LED is turned off and the green "Running" LED is turned on. The green LED will remain on for all other states

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A.O. Smith 650, GB/GW-300, 500, 750 SERIES warranty Description of CCB control states

500, 750 SERIES, 650, GB/GW-300 specifications

The A.O. Smith GB/GW-300, 650, 750 Series, and 500 represent a cutting-edge line of commercial water heaters designed to meet the diverse needs of various applications. These models are highly regarded for their advanced features, robust construction, and reliable performance, making them ideal for businesses such as restaurants, hotels, and industrial facilities.

One of the main features of the A.O. Smith GB/GW series is its high-efficiency design. These water heaters are built with advanced insulation and heat exchanger technology, which contribute to reduced energy consumption and lower operating costs. The products achieve notable energy efficiency ratings, ensuring that businesses can maintain their hot water supply without incurring excessive utility bills.

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In summary, the A.O. Smith GB/GW-300, 650, 750 Series, and 500 are exemplary choices for commercial water heating solutions. Their combination of efficiency, advanced technology, durable design, and comprehensive safety features ensures that businesses have access to reliable hot water, ultimately supporting their operational needs and enhancing service delivery.