Tweco PAK 200i - Manual (Page 150)

PAK 200i
A-70 APPENDIX Manual 0-5335
403 Coolant overheated.
TS1 is a linear negative temperature coefficient (NTC) resistor sensor attached to the brass fitting at the exit of
the bypass valve. Here we determine the coolant being supplied to the torch is below the required temperature
which is currently 75 deg C (167F). The radiator is on the lower right side of the unit. The fan(s) are behind it
and blow out through the radiator. 100A & 200A units may either have 2 smaller fans or one larger one. The
300 & 400A units have one larger one.
Fans operate during cutting and for 4 minutes after last cut then shut off. Exceptions are AC 200 XT and PAK
200i where the fans are on whenever power is on. The external heat exchanger, HE400, fan is thermostatically
controlled so it only comes on when coolant is over 60 deg C. It will shut off when the other fans shut off.
Possible reasons for coolant overheated:
Coolant fan(s) failed or defective fan control relay MC2.
• Radiator fins clogged with dirt.
• Duty cycle exceeded (ambient temperature above 40 deg C and operating at high duty cycle).
• Operating with an object placed in close proximity to the air outlet (right side of the unit) or the front
panel inlet openings.
• Operating for extended time with right lower side panel removed.
• Defective Relay board.
• Defective CCM.
Troubleshooting:
1. Check for air blowing out of the unit. Remember, except for the AC 200 XT and PAK 200i, the fans only run
when CNC START is applied and for 4 minutes after cutting, you may have to apply start again to restart
the 4 minute time. Fans may be forced on by jumping TP2 on the CCM I/O board to TP1 (ground).
a. If using the external HE400XT heat exchanger, optional for 300A, standard for 400A, check for air blow-
ing out of it. Note that the HE400XT fan, controlled by a thermal switch in the HE400XT, only runs if
the coolant is over 60 deg C and the internal fans are operating. With the 100 & 200A if it has 2 fans
make sure both fans are operating by checking for air both top and bottom of the opening. The fans are
difficult to see, perhaps you can use an inspection mirror. Be careful not to get the mirror or your hands
into the blades.
�. Fans are powered by �30 VAC. The �30 VAC for the fan(s) is switched by the MC� control relay (except the
AC 200 XT and PAK 200i where the fan(s) is powered directly from the T1 transformer at J13).
Art # 12311
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
J8
1
5
3
2
4
Fan Bias Control
K4
MC2
Fan Control
(160)
(161)
SA3
ARC_SUPPRESSOR
D24
24 VAC
Relay PCB
230 VAC from T1
MC2A
MC2B
To J70-2
To J70-3
(69)
(70)
(70)
(65A)
(70)
(69)
1
2
3
J73
(64A)
CHASSIS GND
1
2
3
J72 C4
FAN1
R
R
BK
BN
BL
1 2 3 4
J13
TP1 TP2
CCM I/O PCB
To test fan relay jump TP2 to TP1.
+24
J4-19