Troubleshooting/Repair Helps; Hookup - Electro Industries EB-MS-10 Installation & Operating Instructions Manual

TROUBLESHOOTING/REPAIR HELPS

1. This temp. sensing controller contains several interference suppression components, but as an
electronic logic product, unpredictable and unusual transients or interference may sometimes cause
strange results. If the temp. sensing controller is "acting strange", one immediate step would be
power down reset. Simply turn off boiler power or breaker number 1, when the green LED goes out,
count to 10, and re-energize power supply.
2. Inoperative temperature sensor, if the internal program can detect a bad sensor (shorted, open wire,
etc. – not necessarily bad value) the front panel green LED will be pulsing. In this condition there
should be two short blinks every second.
3. The temperature sensor can be further evaluated with diagnostic program from standard PC or WF
Analyzer software. This includes the ability to "fool" the sensor or set in an offset for various
troubleshooting purposes. This software disk comes with a special cable needed for PC or Palm

hookup.

- WF-ANZ* – Handheld/Analyzer
- ET-SOFT-TS – PC software disk and cable
4. The terminal blocks for control wire hook-up are designed for a wire insertion and screw clamp
down. If there is no wire connected and the screw is loose, the screw may not necessarily make a
good electrical contact to the inside components. Example - If you are jumpering the thermostat
terminals without thermostat wire connection or if you are attempting to measure voltage on the
screw head, you may get erroneous or unpredictable results if the screw is not tightened down.
5. Temperature sensing bypass – the inside control board, left side, contains a "E" tab which can be
used to directly step in the heating stages and in essence bypass the temperature sensing and control
functions. The "E" tab has the highest priority and overrides all temperature sensor functions. In
other words, when jumpering from W to E all four stages are hard on. Note: Verify pump is
operating prior to using the E terminal. Since activating this E terminal causes full electric element
output, this function should only be used to verify all stages or troubleshoot proper 24Ø current at
each element.
6. Use general heating system logic information and basic understanding of the terminal block wiring
functions measure various voltage points to determine proper operation.
TEMPERATURE SENSING CONTROL SEQUENCE
See "Heat Cycle", page 9. This sequence picks up after the first stage light or element relay comes on.
1. After the 30-second delay, depending upon how close the temperature is to set point, only stages
1 and 3 may come on or all 4 stages may come on.
2. At a fixed time interval (high mass, 4 minutes or low mass, 2 minutes) the outlet temperature is
compared to the set point. If it is below or above the minimum fixed point, there is no change in
staging.
3. If it is below the minimum range (high mass, 5° or low mass, 3°), add the next lowest stage.
4. If it is above the minimum range, drop the lowest stage.
5. If it is a major temperature differential above set point, drop the two lowest stages.
6. Cycle repeats at each time interval.
7. At the start of turn on, a 30-minute SOT timer begins. If the outlet temperature equals set point at
any time, this 30-minute timer is stopped. If the 30-minute timer actually timed-out, all stages are
turned on.
8. There is also a built-in controller or electronic hi-limit (high mass, 150° or low mass, 186°).
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