Tweco 6000 CE Merlin - Manual (Page 36)

INSTALLATION PROCEDURES 3-18 Manual 0-2601
The reason is because within each range the Power
Supply will automatically select a high or low tap
on the transformer secondary. This is based on
the input AC line voltage at the time the Power
Supply is turned ON. If the line voltage is near
one of these points the voltage might measure, for
example, 410 VAC and the pilot resistor setting
should be 9 ohms to have a good pilot. The next time
the system is turned ON, the input AC line voltage may
have gone up to 420VAC causing the pilot to sputter
because 420VAC requires setting of 4.5 ohms.
Pilot Resistor Setting vs. Input Line Voltage
Input (VAC) Ohms
340 5
350 5.5
360 6
370 6.75
380 7.25
390 8
400 8.5
410 9
420 4.5
430 5
440 5.5
450 6
460 6.5
470 7
480 7.5
490 8
500 8.5
510 9
6. Wires are attached to the pilot resistors with metal
clamps or taps. Locate and loosen the screw that
secures the wire #99 tap on resistor R16. Deter-
mine, from the Figure below, the correct position
for the tap on R16 and tighten the screw.
Example:
To set for 6 ohms measure 5” from the right side
of R16, where wire # 96 attaches, and secure the
#99 tap at that position.
Pulser
99 150
Wire #99
Tap
9.0 ohms
At End
R16 (4.5 ohms)
R22 (2.2 ohms)
R21 (2.2 ohms)
Temp Switch
Wire
#96A
Wire #150
Tap
Wire #74
8.5 ohms
12.8" (305 mm)
8.0 ohms
11.2" (279 mm)
7.5 ohms
9.6" (242 mm)
7.0 ohms
8.1" (203 mm)
6.5 ohms
6.5" (164 mm)
6.0 ohms
5.0" (127 mm)
5.5 ohms
3.4" (87 mm)
5.0 ohms
1.9" (44 mm)
4.4 ohms
At End
Wire #96
4.4 ohms
At End
5.0 ohms
13.7" (344 mm)
5.5 ohms
12.3" (311 mm)
6.0 ohms
10.8" (255 mm)
6.5 ohms
9.4" (237 mm)
7.0 ohms
8.0" (203 mm)
7.5 ohms
6.5" (164 mm)
8.0 ohms
5.1" (127 mm)
8.5 ohms
3.7" (90 mm)
9.0 ohms
2.5" (63 mm)
A-01852
Figure 4-5 Resistance Value Diagram
7. The pilot pulse value is set by positioning the wire
#150 tap on resistor R22. Locate and loosen the
wire #150 tap. From the above Figure find the
ohms value that corresponds to the value that the
wire #99 tap was set to. Measure distance indi-
cated from the right side of R22, where wire #96
attaches and secure the wire #150 tap there.
NOTE
The ohm value shown for the wire #150 tap does
not represent the value of the R22 resistor but in-
stead corresponds to the total resistance of R16,
R22 and R22 set by the wire #99 tap.
8. Test the pilot, if it still sputters move the wire #99
tap to the right, toward wire #96, 1 inch (25.4 mm)
at a time until the pilot no longer sputters.
9. Once there is a good steady pilot, test for the de-
sired transfer height. If the transfer height is not
high enough, between 3/8 inch (9.5 mm) to 1/2
inch (12.7 mm), move the wire #150 tap to the left
on R22, 1 inch (25.4 mm) at a time, until the de-
sired height is obtained.