TurboChef Technologies 2020 User Manual
Page 40
2 2
O V E N S YS T E M S
Testing Procedure
1. Disconnect line voltage to the unit.
2. Take a resistance reading of the coil.
3. If coil resistance is correct (585
W
):
a) Apply line voltage to the unit.
b) Check for 24 VDC at the coil of the
relay when the unit is calling for heat.
c) Check the state of the contacts.
-If the normally open contacts (7 & 4
-
or C & NO) are closed when coil
-
voltage is applied, the relay is
-
functioning normally.
-If the normally open contacts (7 & 4
-
or C & NO are not closed when coil
-
voltage is applied, the relay must be
replaced (page A-7 and A-8).
4. If the coil resistance is incorrect, replace the
relay.
Relay, Solid State - K5/K4 Heaters
The solid state relay is a 240 VAC, dual 40-amp
relay, and switches power to the heaters.
RTD
The RTD is a resistance temperature detector
used to detect the cavity temperature.
Testing Procedure
1. Disconnect the RTD from the I/O control
board.
2. Place the RTD in a bowl of ice water for 2
minutes.
3. Take a resistance reading of the RTD.
4. If RTD resistance is not 100
W
, RTD is
defective and must be replaced.
NOTE: Use Figure 32 to determine resistance
readings at temperatures other than freezing.
Smart Card Reader
The smart card reader allows the oven operator
to load a menu/firmware update from a smart
card. A menu that already exists in the oven can
also be saved to a smart card. For instructions,
see page 15.
Speaker
The speaker is separate from the control board,
and provides audible feedback to the oven oper-
ator whenever a key is pressed or a fault occurs.
Thermostats - 120ºF (Close on Rise)
The cooling fan thermostats actuate the cooling
fans when the temperature in either end bell
reaches or exceeds 120ºF (49ºC).
Wire Harness
The wire harness distributes power to the oven’s
electrical components. See pages 37-40 for
schematics.
ºF
0º
+20º
+40º
+60º
+80º
+100º
+120º
+140º
+160º
+180º
+200º
0º
90.03
W
97.39
W
101.74
W
106.07
W
110.38
W
114.68
W
118.97
W
123.24
W
127.50
W
131.74
W
135.97
W
+200º
135.97
W
140.18
W
144.38
W
148.57
W
152.74
W
159.90
W
161.04
W
165.17
W
169.29
W
173.39
W
177.47
W
+400º
177.47
W
181.54
W
185.60
W
189.64
W
193.67
W
197.69
W
201.69
W
205.67
W
209.64
W
213.60
W
217.54
W
+600º
217.54
W
221.47
W
225.38
W
229.28
W
233.17
W
237.04
W
240.90
W
244.74
W
248.57
W
252.38
W
256.18
W
ºC
0º
+10º
+20º
+30º
+40º
+50º
+60º
+70º
+80º
+90º
+100º
0º
100.00
W
103.90
W
107.79
W
111.67
W
115.54
W
119.40
W
123.24
W
127.07
W
130.89
W
134.70
W
138.50
W
+100º
138.50
W
142.29
W
146.06
W
149.82
W
153.58
W
157.31
W
161.04
W
164.76
W
168.46
W
172.16
W
175.84
W
+200º
175.84
W
175.91
W
183.17
W
186.82
W
190.45
W
194.07
W
197.69
W
201.29
W
204.88
W
208.45
W
212.02
W
+300º
212.02
W
215.57
W
219.12
W
222.65
W
226.17
W
229.67
W
233.17
W
236.65
W
240.13
W
243.59
W
247.04
W
Figure 32: Temperature/Resistance Relationship Class B. Resistance @ 0ºC = 100.0, Alpha = 0.003850