Troubleshooting Water Modulating Actuator Diagnostics - Bard Q-TEC Series Literature Assembly

FIGURE 38
LED Fault Illumination
Green Status Light
TROUBLESHOOTING WATER
MODULATING ACTUATOR
DIAGNOSTICS
The Bard QW*S3D Series is equipped with a water
modulating actuator. The water modulation is achieved
through the operation of a TACO iSeries Smart
Actuator, attached to a TACO 3-way valve.
The iSeries Smart Actuator is a microprocessor-based
valve designed to provide a setpoint (fixed) temperature
to a HVAC system by modulating the position of a
mixing valve. The iSeries Smart Actuator is shown in
Figure 39.
HP = Green Fault
Illumination
LP = Orange Fault
Illumination
Troubleshooting the iSeries Smart Actuator
As in any troubleshooting procedure, it is important
to isolate a problem as much as possible before
proceeding. The error message greatly simplifies
troubleshooting of the iSeries-S. When the control
FS (Evap) =
Red Fault
flashes an error message, identify the fault by
Illumination
observing the LED status light code and follow
standard testing procedures to confirm the problem.
The LED status code and error can be diagnosed by
following the light sequences in the multi-status LED
table (Table 14).
CO = Yellow Fault
Illumination
If a wiring fault is suspected, return to the wiring
diagram located on the unit door and carefully
inspect all external wiring and wiring connections.
LED
Green
Red
Testing the Sensors
A good quality test meter capable of measuring up
to 5,000 kΩ(1 kΩ= 1000 Ω) is required to measure
the sensor resistance. In addition to this, the actual
temperature must be measured with a good quality
digital thermometer.
First measure the temperature using the thermometer
and then measure the resistance of the sensor at the
iSeries Smart Actuator. The wires from the sensor
must not be connected to the iSeries Smart Actuator
FIGURE 39
iSeries Smart Actuator
BOILER
POWER = GREEN
SUPPLY
SENSOR
= RED
ERROR
OUTDOOR
TABLE 14
Multi-Status LED
LED Status ISeries Smart Actuator Status
Solid Power On
Reduced Output
Flash
(System Protection Activated)
Flash, Pause, System Supply Sensor Fault
Flash, Pause, The iSeries-S operates at a
Flash, ... fixed output
STATUS LIGHT
C R
24 VAC
POWER INPUT
SENSOR
COMMON
MIS-4135
Manual 2100-738A
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