51
STS INSTALLATION, OPERATION, AND MAINTENANCE MANUAL
INSPECTION AND MAINTENANCE
1.
Annually
(also recommended when maintenance is performed)
•
All safety devices in the control circuit should be cycled on and off to
verify they are functioning. These include:
– High limit switch
– Airfl ow proving switch
–
Low water level probe. Pull out probe plug; fi ll valve should energize.
• Inspect tank and gaskets for leaks.
2.
Seasonally
(or as required, depending on water quality)
• Cleaning the tank
–
Remove cleanout plate and dispose any loose scale that has
collected in the bottom of the tank. This should be done before the
scale buildup reaches the bottom of the heat exchanger.
–
Inspect the area inside the tank in front of the drain valve fi tting, and
thoroughly clean all scale and mineral buildup from that area.
• Cleaning the probes
–
Disconnect the probe plug and cable assembly (located on top of the
tank), and unscrew the probe rod assembly from the humidifi er probe
housing using the probe tool (see Figure 51-1).
–
Inspect the probe housing and clean, ensuring that all housing
passageways are clear. To detach the housing from the tank, remove
the four bolts that attach it to the tank. Then lift the housing up out of
the tank.
– The scale should fl ake off easily from the probe assembly rods.
–
The bottom 3/8" (10 mm) is the sensing portion of each probe rod;
it should be brushed clean with a wire brush, abrasive pad, or steel
wool.
–
Inspect the composite plastic probe rod assembly for any signs
of cracking, roughness, or deterioration. If found, replace probe
assembly.
– Reassemble the probe rod assembly, and torque as indicated in
Figure 51-1.
Tap/softened water
MAINTENANCE
WARNING
Shutdown procedure
To prevent serious injury, follow this
shutdown procedure before performing
service or maintenance procedures on
this humidifi er (after the tank has cooled
down and drained):
1. Use Vapor-logic keypad/display to
change control mode to Standby.
2. Place all power disconnects in OFF
position and lock in OFF position.
3. Close the fi eld-installed manual
water supply shut-off valve.
4. Close the manual shut-off valve on
the inlet steam supply.
Remove and install probe assembly with
supplied probe tool. Attach a 3/8" square
drive to the probe tool.
When installing, torque probe assembly to 120
in-lbs (10 ft-lbs; 13.6 N-m). Probe tools can be
ordered from your DriSteem representative (Part
no. 185101).
Probe tool
OM-7395X
mc_060310_0735
FIGURE 51-1: PROBE TOOL
