Over-Temperature Limit Switches; Digital Alarm Switch Checks And Adjustments - Watts Aerco Benchmark OMM-0124 Installation And Start-Up Manual

Natural gas, propane gas and dual fuel fired modulating & condensing boilers
Table of Contents

Advertisement

Benchmark 5000-6000 Boiler Installation & Startup Manual
SECTION 4: INITIAL START-UP

4.8 OVER-TEMPERATURE LIMIT SWITCHES

The unit contains three (3) types of over-temperature limit controls. These controls consist of a
Manual Reset button, a rotary adjustable Temperature Limit switch and a digital Over-
Temperature Alarm button. These controls are mounted on a plate as shown in Figure 4-5. They
can be accessed by opening the front panel door of the unit.
The Manual Reset button is not adjustable and is permanently fixed at 210°F (98.9°C). This
button will shut down and lock out the boiler if the water temperature exceeds 210°F (98.9°C).
Following an over-temperature condition, it must be manually reset by pressing the Manual
Reset button shown in Figure 4-5 before the boiler can be restarted.
The adjustable Temperature Limit switch is manually adjustable from 32ºF - 212ºF (0ºC –
100ºC). This switch allows the boiler to restart, once the temperature drops below the selected
temperature setting on the dial. Set the dial on this switch to the desired setting.
The digital Over-Temperature Alarm switch shown in Figure 4-5 and 4-6 is preset at the factory
to 210ºF (98.9°C) and should not be changed. If an over-temperature condition is detected, this
switch automatically shuts down the boiler and sounds an audible alarm. If desired, the Over-
Temperature Alarm can be checked or adjusted using the procedure in Section 4.8.1.
Figure 4-5: Over-Temperature Limit Switch Location

4.8.1 Digital Alarm Switch Checks and Adjustments

The Over-Temperature Alarm switch settings can be checked or adjusted using the controls
and display on the front panel of the switch illustrated and described in Figure 4-6 and
Table 4-6.
Figure 4-6: Digital Over-Temperature Alarm Switch Front Panel
OMM-0123_E • GF-207 • 12/17/2019
Technical Support • (800) 526-0288 • Mon-Fri, 8 am - 5 pm EST
ADJUSTABLE TEMPERATURE
LIMIT SWITCH (AUTO-REST)
DIGITAL OVER-TEMPERATURE
LIMIT CONTROLLER
RESET BUTTON FOR MANUAL
TEMPERATURE LIMIT SWITCH
MANUAL TEMPERATURE LIMIT
SWITCH
Page 61 of 95

Advertisement

Table of Contents
loading

Table of Contents