BOILER SEQUENCE OF OPERATION WITH PROBE LWCO (See Figure 18)

When the thermostat calls for heat, it energizes the R8285C Control Center relay which in turn energizes the cad cell primary control, bringing on the burner. The burner will operate in the following sequence: Prepurge for the first 10 seconds; fire until the thermostat is satisfied or the limit setting on the high limit is reached; post-purge for the last 10 seconds. When the pressure limit control restores the circuit on a drop in pressure, the burner will start if the thermo- stat is still calling for heat.

The probe low water cut-off will shut down the burner after a 10-15 second delay, if the water level in the boiler drops below the probe level.

The Hydrolevel CG450 low water cut-off will shut down the burner for 90 seconds every 10 minutes of firing time to allow water level to stabilize. If the water level is too low the burner will not be allowed to restart.

The probe low water cut-off will reset and restart the burner with a call for heat a few seconds after the water is re- turned to its normal level.

On burner start, if the cad cell does not see flame within approximately 15 seconds, primary control will shut burner down and enter into a recycle mode, after 60 seconds burner will restart and repeat trial for ignition. If after three

(3)trials for ignition, flame is not detected, control will enter into restricted mode and must be reset manually before burner can be restarted.

When there is no demand for heat, the operating control will maintain the boiler water temperature at the selected setting for proper operation of the domestic water heater, if equipped with optional tankless heater.

BOILER SEQUENCE OF OPERATION WITH PROBE LWCO (See Figure 19)

When the thermostat calls for heat, it energizes the R8285C Control center relay, which in turn energizes the cad cell primary control, bringing on the burner. The burner will operate in the following sequence: Prepurge for the first 10 seconds; fire until the thermostat is satisfied or the limit setting on the high limit is reached; post-purge for the last 10 seconds. When the pressure limit control restores the circuit on a drop in pressure, the burner will start if the thermostat is still calling for heat.

The probe low water cut-off will shut down the burner after a 10-15 second delay, if the water level in the boiler drops below the probe level.

The probe low water cut-off will reset and restart the burner with a call for heat a few seconds after the water is returned to its normal level.

On burner start, if the cad cell does not see flame within approximately 15 sec- onds, primary control will shut burner down and enter into a recycle mode, after 60 seconds burner will restart and repeat trial ignition. If after three (3) trials for igni- tion, flame is not detected, control will enter into restricted mode and must be reset manually before burner can be restarted.

When there is no demand for heat, the operating control will maintain the boiler water temperature at the selected setting for proper operation of the domestic water heater, if equipped with optional tankless heater.

McDonnell & Miller PS-801 Terminals May be Lettered or Numbered as Follows:

Wire

Numbered

Lettered

Color

Terminals

Terminals

RD

5

B

BK

1

H

WH

2

N

Jumper

1-3

H-C

BOILER SEQUENCE OF OPERATION WITH FLOAT LWCO (See Figure 20)

When the thermostat calls for heat, it energizes the R8285C Control center relay, which in turn energizes the cad cell primary control, bringing on the burner. The burner will operate in the following sequence: Prepurge for the first 10 seconds; fire until the thermostat is satisfied or the limit setting on the high limit is reached; post-purge for the last 10 seconds. When the pressure limit control restores the circuit on a drop in pressure, the burner will start if the thermo- stat is still calling for heat. The low water cut-off will shut down the burner if the water level in the boiler drops too low. The control resets and restarts the burner with a call for heat a few seconds after the water is returned to its normal level.

On burner start, if the cad cell does not see flame within approximately 15 seconds, primary control will shut burner down and enter into a recycle mode, after 60 seconds burner will restart and repeat trial for ignition. If after three

(3)trials for ignition, flame is not detected, control will enter into restricted mode and must be reset manually before burner can be restarted.

When there is no demand for heat, the operating control will maintain the boiler water temperature at the selected set- ting for proper operation of the domestic water heater, if equipped with optional tankless heater.

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Image 36
Burnham MST288, MST396, MST629, MST513 manual Boiler Sequence of Operation with Probe Lwco See Figure
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MST513, MST396, MST629, MST288 specifications

The Burnham MST series, comprising models MST396, MST629, MST513, and MST288, is renowned for its robust design and exceptional performance in the boiler industry. Each model is engineered to provide optimal efficiency and reliability for residential and commercial heating applications.

The Burnham MST396 is distinguished by its high thermal efficiency and advanced combustion technology. This model features a cast iron heat exchanger which ensures superior heat retention and distribution. The MST396 is equipped with a powerful burner that allows for variable firing rates, maximizing efficiency and extending the lifespan of the unit. Additionally, it includes a built-in electronic ignition system that enhances reliability while reducing the need for frequent maintenance.

Moving to the MST629, this model is designed for larger applications needing higher output. It boasts a significant BTU input and utilizes a multi-stage burner system. This ensures optimal combustion and adapts to varying demand, providing consistent heat without wasting energy. The MST629 also incorporates enhanced insulation and an advanced flue gas venting system to improve safety and minimize energy loss.

The MST513 caters to mid-sized applications with its adaptable performance and user-friendly features. This model is notable for its compact design, making it suitable for installations with limited space. It uses a two-stage burner for efficient energy use and offers a smart control system that monitors performance in real-time. This allows users to make informed decisions about their energy consumption and maintenance needs, ultimately leading to cost savings.

Lastly, the MST288 is the smaller model in the series, ideal for homes and small businesses. Despite its size, it does not compromise on efficiency. The MST288 features a straightforward design, ensuring ease of installation and maintenance. It utilizes a single-stage burner that provides consistent heat output, making it a reliable choice for low-demand applications. The unit is also equipped with adjustable settings, allowing users to tailor their heating needs effectively.

In summary, the Burnham MST series demonstrates a remarkable blend of innovation and practicality across its models. With features like advanced burner technology, efficient heat exchangers, and smart controls, the MST396, MST629, MST513, and MST288 cater to a wide range of heating needs while prioritizing energy efficiency and user comfort. These models stand out in the market, continually setting a standard for performance and reliability in heating solutions.
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