Hypertherm HD3070 Plasma Arc Cutting System w/ Automatic Gas Console - Manual (Page 137)

5-12 HD3070 with Automatic Gas Console Instruction Manual
16
MAINTENANCE
5. The green POWER ON
indicator is lit, the torch
START command is
given and the red DC ON
indicator lights, and
there is high frequency,
but there is no pilot arc.
5.1. Pilot arc relay CR1 is not closing (not getting 120VAC
from the Relay Board 1XPCB4).
See if the CR1 relay contacts close after the START
command is given. See Figure 6-7 for location of CR1.
If CR1 does not close:
• With an AC voltmeter across the relay, see if 120VAC
is coming from 1XPCB4 after START command is
given.
• If there is no 120VAC, check connectors, terminals,
pins, and associated wiring to REC3 of 1XPCB4.
• If wiring is OK, there is a problem either with 1XPCB4
or 1XPCB3.
5.2. Pilot arc relay CR1 is defective.
If there is 120VAC across the relay (see above steps),
and CR1 does not close, replace CR1.
5.3. Main contactor (CON1) or 1XPCB4 is defective.
• With an AC voltmeter, see if contactor CON1 is getting
120VAC after START command is given.
If there is no 120VAC, check pins, connectors and
associated wiring from CON1 to pins 5 & 6 of REC3 of
1XPCB4.
See Relay Board (1XPCB4) later in this section for
location of relays and description of output signals.
• If there is 120VAC at FL1, shut down system and
remove capacitors C3 and C4. (See Figure 6- 11 for
location of C3 and C4) Restart system and see if a
faint spark is now observed across the gaps.
• If a spark is not observed at the gaps, replace T1.
If there is a spark, shut down system, and replace
capacitors C3 and C4. (Always replace the
capacitors in pairs).
4.2. There is no high frequency at the torch.
Check for a shorted torch, a damaged pilot arc lead, or
loose lead connections. Replace the torch or pilot arc
lead or tighten the lead connections.
Problem Possible Causes / Solutions