Xylem MM 273E Model 750-HW-MT-120 Probe Type High Water Manual Reset Control Unit - Manual (Page 7)

7
R
D (x2)
Model 750-HW-MT-120
Probe Type High Water
Control Unit
d. Secure the control housing cover by using the
flatblade screwdriver or nut driver (R) to tighten the
two (2) screws (D) to approximately 2 ft•lb (2.6 N•m).
c. Secure the sensor housing cover (Q).
1. For model RS-1-BR-1, using the flatblade screw-
driver (R), tighten the four (4) screws into the
housing (Q) to approximately 3 ft•lb (4 N•m).
2. For model RS-1-LP, using the flatblade screw-
driver or nut driver (R), tighten the two (2) screws
into the housing (Q) to approximately 2 ft•lb (2.6 N•m).
Q
R
R
Q
OR
Model RS-1-BR-1 Model RS-1-LP
STEP 5 -Testing and Diagnostic Procedures
Start-Up
a. Before filling the system, turn on the electric power to the boiler.
1. Upon initial power up, the Green and Red lights will flash simultaneously
4 times.
2. The Green light will turn "ON".
3. The Red light will turn "OFF" and the burner will turn “ON” as long
as there is water off the probe.
Manually Testing Control
b. Slowly fill the boiler with water.
1. When water touches the probe, the Green light will remain "ON".
2. The Red light will turn “ON” and the burner will turn “OFF”, when
water touches the probe.
Testing Control Using "Test Button"
c. Depressing test button with "water off probe”
(Must depress and hold test button to activate test cycle.)
1. When test cycle is activated the Red and Green lights will flash simultaneously
2. The Red light will turn "ON".
3. Burner will turn "OFF".
4. The Green light
while the test button is depressed.
(Release test button. You must depress the manual reset button to unlock the high water cut-off.)
5. After depressing manual reset button, the Green and Red lights will flash simultaneously 4 times.
6. Then the Green light will turn "ON" and the Red light will turn "OFF".
7. The burner will turn "ON" if
5-1/2"
Test
Green
Power On
Red
High
Water
Reset Button
Model 750-HW-MT-120
Probe Type High Water
Control Unit
stays "ON"
the water is off the probe.
twice.