16
installation
&
operation
manual
|
dlv
heating
system
5.2.11 TEMPERATURE CONTROL RELAY (TCR)
WARNING
!
Hazardous voltage:
Before wiring, servicing or cleaning the heating system, turn off the power and follow
your organization’s lockout and tagout procedure. Failure to do so could allow others to turn on the power
unexpectedly, resulting in harmful or fatal electrical shock.
If the DLV heating system does not maintain the desired preset control temperature or consistently signals
a high-limit temperature fault, the TCR (temperature control relay) , the RTD (resistance temperature
device), or the RTD cable may require replacement. To perform this troubleshooting, you will need:
•
Ohmmeter
1.
De-energize the heating system. Check the temperature gauge
to ensure the liquid in the tank is below 122 °F (50 °C).
2.
Using the ohmmeter, measure the resistance between TCR
terminals
O1
and
O2
.
See Fig. 7
.
h
If the measured resistance is
between 80 and 120 ohms
continue troubleshooting.
Proceed to step 3
.
h
If the resistance is
lower than 80 ohms
or
higher than 120
ohms
, contact HOTSTART for further assistance.
3.
Use the ohmmeter to test for continuity between TCR terminals
O2
and
O3
.
h
If there
is continuity
between TCR terminals
O2
and
O3
and the
DLV does not maintain temperature or consistently signals a high
limit fault, the TCR requires replacement. Contact HOTSTART
for further assistance.
h
If there
is no continuity
between TCR terminals
O2
and
O3
,
locate the connected RTD on the heating tank. Unscrew the RTD
plug from the RTD.
See Fig. 9 and Fig. 10 on following page
.
4.
Using the ohmmeter, touch the probes to RTD
pin 1
and
pin 3
.
See Fig. 8
. Note the resistance. Touch the probes to RTD
pin 1
and
pin 4
to check for continuity.
h
If the resistance between RTD
pin 1
and
pin 3
is
between 80
and 120 ohms
and
there
is continuity
between RTD
pin 1
and
pin 4
, the RTD is functioning properly. Replace the RTD cable.
h
If the resistance between RTD
pin 1
and
pin 3
is
not between
80 and 120 ohms
or
there
is no continuity
between
pin 1
and
pin 4
, the RTD is malfunctioning. Replace the RTD.
See
SECOIO 5.2.12
.
Figure 8. RTD pins 1, 3 and
4. The resistance between
pin 1 and pin 3 should
measure between 80 and
120 ohms. There should be
continuity between pin 1
and pin 4.
100
100
0
0
11
12
11
12
13
14
A2-
13
14
A2-
A3
A1
A3
A1
T1
T2
T3
T1
T2
T3
PIN 1
(BROWN
WIRE)
PIN 3
(BLUE
WIRE)
PIN 4
(BLACK
WIRE)
Figure 7. Coolant
(TCR1) and oil (TCR3)
control TCR showing
terminals T1 (blue wire),
T2 (brown wire) and T3
(black wire).
