Page 26 | ΒΡΑΔΦΟΡΔ ΩΗΙΤΕ ΧΟΡΠ. |
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tank is drawing down, the heater will react to sustain a minimum tank temperature. Boilers generally have higher differentials than water heaters, to minimize short cycling (see throttling range). The differential is set by removing the cover of the A350 control and adjusting the potentiometer marked “DIFF” (see Figure 13).
5.5.3Offset
The offset determines the temperature below the controller’s setpoint where the throttling range begins. It offsets the throttling range.
For instance, if the setpoint is 120°F (49°C) and the offset is 5°F (3°C), then the unit’s throttling range will begin at 115°F (46°C). Between 115°F (46°C) and 120°F (49°C), the Brute Magnum will be in low fire.
The offset can be adjusted between 0°F and 30°F (0°C and 17°C) by removing the cover of the S350P control and adjusting the Offset dial (see Figure 14).
5.5.4Throttling Range
The throttling range allows the Brute Magnum to match the BTU demands of varying systems, by allowing the user to choose the temperature range
through which the unit will modulate. This will tell the controller how fast to respond to a change in temperature. A small throttling range keeps the unit in high fire more, and quickens the response of the system. A larger throttling range allows the Brute Magnum to spread its modulating range over a larger temperature range.
Example, Imperial units: Using a temperature setpoint of 120°F, with a 20°F differential, a 5°F offset, and a throttling range of 10°F, the unit will come on at 100°F and shut off at 120°F. The offset will set the top of the throttling range 5°F under the setpoint, which is 115°F in this example. Therefore, the throttling range will cause the Brute Magnum to modulate between 25% and 100% of full fire between 115°F and 105°F. Between 115°F and 120°F, the unit will remain at low fire. Between 100°F and 105°F, the unit will be at full fire.
Example, Metric units: Using a temperature setpoint of 49°C, with a 11°C differential, a 3°C offset, and a throttling range of 5°C, the unit will come on at 38°C and shut off at 49°C. The offset will set the top of the throttling range 3°C under the setpoint, which is 46°C in this example. Therefore, the throttling range will cause the Brute Magnum to modulate between