Hach 900 Indoor Furnishings User Manual


 
Page 36
Motor/Gear Box
8544Maintenance.fm
Section 5
5.10 Motor/Gear Box
The motor/gear box requires no regular maintenance. The special formulation
gears are self lubricating and require no oil or grease.
5.11 Internal Case Humidity Indicator
After replacing the desiccant module and re-sealing the case, the Internal
Case Humidity indicator disc (Cat. No. 2660) should return to its original blue
color. Replace the indicator disc if it fails to return to blue after replacing the
desiccant module. To replace the indicator disc, remove the bottom panel that
is held in place by a small clip and screw.
5.12 Internal Case Humidity Indicator
The humidity indicator is located on the left front side of the controller. If the
humidity indicator is blue, the desiccant is dry. If the indicator turns pink or
white, inspect the electronics housing for seal failure and replace the
desiccant module.
5.13 Memory Battery
Random Access Memory (RAM) is a very reliable data storage medium for
microprocessor applications. However, RAM requires power at all times. If
power is removed, the data stored in the RAM chip is lost. Therefore, you
cannot power the RAM chips from the 900 Composite Sampler power supply
because you would lose data and program settings every time you unplugged
the power cord. A separate battery located inside the sampler controller is
provided to power the RAM chips and the real-time clock. The memory
battery keeps the program entries and logged sample data alive inside the
RAM memory when the main power fails or is removed for transport or
replacement.
The 900 Composite Sampler memory battery consists of a 1.5 V dc Lithium
cell. The battery is soldered to the main circuit board.
Should the memory battery voltage fall too low to properly maintain the
program settings, a warning:
MEMORY POWER LOW will alert you to replace
the battery. The 900 Composite Sampler utilizes a very small amount of
energy from the memory battery during normal operation. The service life of
the batteries in this application is typically five years.
1. Desiccant module slides under circuit board 6. J5 Distributor/Full Bottle Shut-off
2. J8 LCD Display 7. J2 12 V dc
3. J6 Auxiliary 8. J3 Fuse
4. J1 Liquid Sensor 9. J4 Motor
5. Lithium Memory Battery 10. J9 Keypad