User manual

Northern Industrial Welding
7
Operating Instructions and Parts Manual
ST80i
-Always have power disconnected
when working on internal
components.
- Do not touch or handle PC board
without being properly grounded
with a wrist strap. Put PC board in
static proof bag to move or ship.
-Do not put hands or fingers near
moving parts such as fan.
Assembly
This unit is assembled when out of
factory.
Installation
1. Power requirement
AC single phase 120v (110-120V),
60HZ fused with a 20amp time
delayed fuse or circuit breaker is
required. DO NOT OPERATE THIS
UNIT if the ACTUAL power source
voltage is less than 105 volts ac or
greater than 132 volts ac.
• High voltage danger from power
source! Consult a qualified
electrician for proper installation of
receptacle. This welder must be
grounded while in use to protect
the operator from electrical shock.
• Do not remove grounding prong
or alter the plug in any way. Do
not use any adapters between the
welder’s power cord and the power
source receptacle. Make sure the
POWER switch is OFF when
connecting your welder’s power
cord to a properly grounded
120Vac, 60Hz, single phase, 20
amp power source.
2. Extension cord
During normal use an extension cord
is not necessary. It is strongly
recommended that an extension cord
should not be used because of the
voltage drop they produce. This drop
in voltage can affect the performance
of the welder. If you need to use an
extension cord it must be a #12
gauge cord at the smallest.
-Do not use an extension cord over
25 ft. in length.
3. Setting up the work piece
3.1 Welding positions
There are two basic positions, for
welding: Flat and Horizontal. Flat
welding is generally easier, faster,
and allows for better penetration. If
possible, the work piece should be
positioned so that the bead will run on
a flat surface.
3.2 Preparing the Joint
Before welding, the surface of work
piece needs to be free of dirt, rust,
scale, oil or paint. Or it will create
brittle and porous weld. If the base
metal pieces to be joined are thick or
heavy, it may be necessary to bevel
the edges with a metal grinder. The
correct bevel should be around 60
degrees. See following
picture:
Based on different welding position,
there are different welding joint, see
following images for more information