Munters R Series, Руководство по эксплуатации и техническому обслуживанию

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Manual# I27028 7-7 Rev. 2 – 11/22/2017
7.7 CHECKING THE FLAME ROD SENSOR
1. The flame rod sensor checks for flame during the start-up process. When the gas is
turned on, the ignitor begins to spark. If the flame rod does not detect the flame
within a few seconds, the gas is shut off. The dehumidifier will shut down and lock
into a fault condition.
2. The circuits used with the flame rod are very sensitive to current flow. If the
connections in the circuit are loose, or the wires are not grounded properly, the
controller may not get the signal from the flame rod. A cracked insulator or a wet
wire could cause the same problem. Any of these conditions could prevent the unit
from starting.
3. If the outside of the rod is corroded, this could keep the sensor from operating
correctly. Use a fine-grade steel wool (#0000) to gently remove any rust.
7.8 CHECKING THE HUMIDISTAT (OPTIONAL)
1. Start by adjusting the humidistat to the high end of the scale (close to 100% relative
humidity). At this point, the humidistat should not be calling for drying. The
contacts inside the humidistat should be closed, and 0VDC should be present
across the contacts.
The contacts inside the humidistat carry 24VDC. Shorting of the
leads could result in failure of fuses within the electrical
enclosure.
2. Next, adjust the humidistat to the low end of the scale (close to 10% or 20% relative
humidity). Now the humidistat should be calling for drying, and the contacts inside
the humidistat should be opened. 24VDC should present across the contacts.
3. The wiring between the humidistat and the unit can also be checked. See the wiring
diagram included in this manual. When the humidistat is not calling for
dehumidification, 0 VDC should be present across the contacts. When the
humidistat does call for dehumidification, the voltage across the terminals should be
24VDC.
7.9 CHECKING THE THERMOCOUPLES
R-Series have two thermocouples: TC01 and TC02. Because of the way these parts
operate, they cannot be checked with a voltmeter. If a thermocouple fails, it usually
does so in an “open-circuit” condition. It is possible to check continuity through the
suspect unit with an Ohmmeter. Be sure to turn off the R-Series unit before performing
this check. Disconnect one of the leads, so other circuitry will not affect the reading.
7.10 TROUBLESHOOTING USING THE PLC
The R-Series unit is controlled by a “programmable logic controller” or “PLC.” The PLC
is a small computer which executes a simple set of commands or “program.” The
program is organized as a loop which repeats continuously.
The PLC is mounted inside the control enclosure. Three LEDs on the front of the PLC show
the status of the PLC itself. See
Figure 7-2 and the following table.
The following table may help to interpret the three LEDs.