Installation, operation and maintenance instructions
High voltage flameproof motors for explosive atmosphere
AMD Rg 355-400-450-500
Foundations and fastenings – Horizontal arrangment
Issued by: MOLM
Sheet No.
3AAM101029 E
Rev. B
Page 1 of 3
01.2023
We
res
erv
e
a
ll r
ig
hts i
n t
hi
s
doc
um
ent
a
n
d i
n t
he
in
for
mat
ion
cont
ain
e
d ther
ei
n. R
epr
o
duc
tion
,
us
e
of
di
sc
los
u
re
to
th
ird
pa
rt
ies
w
itho
ut
expr
ess
au
th
ori
ty
is
s
tr
ic
tly
f
orbi
dd
en
.
1. Fastening elements
The feet of the machine are provided with holes for the
fastening bolts and with threaded holes for the leveling
screws; dowel pins holes are sometime provided
according to the design request.
The fastening elements and the shims to adjust the
center height are not usually supplied with the machine;
look at the specific technical documentation for the
required dimension of these elements.
If the shims, the screws and the dowel pins (if any) are
part of the order, they will be delivered as separate
items.
2. Foundation
The responsibility for the design and construction of the
foundation lies with the civil engineer commissioned for
this work. Check prepared foundation and any
ventilation ducts provided for conformity with the
machine outline drawing and foundation plans and make
any necessary correction.
Foundations
free
from
external
vibration
are
recommended.
The foundation (or the steel base fixed to the floor) must
be strong and rigid, in order to avoid any resonance of
the system with the force produced by the motor in
normal and abnormal working condition.
The installation of the motor (and of the driven machine)
on a steel base having flexible pads requires special
design considerations and is therefore a condition out of
standard. The design for this special condition shall be
clearly indicated on the outline drawing.
Important!
It is essential that the motor feet are supported along
their full surface by the steel base or sole plates.
The foundation should be able to withstand sudden
mechanical torque, which occurs at the machine starting
or in case of abnormal conditions.
The values of the stresses imposed on the foundation in
normal and abnormal working condition are reported by
the specific technical documentation.
The upper level of the foundation or of the steel base
shall permit a shimming of about 2 mm, but in any case
not more than 4 mm (in order to avoid possible alteration
of the mounting rigidity of the motor on the basement);
this requirement is based on the shaft centre tolerance
(that is +0 / - 1 mm respect the dimension indicated on
the outline drawing) and makes easy the future
installation of possible replacement machine.
Warning!
The explosion proof motors have a very reduced
backlash between the bearings anti-fire seals and the
rotor shaft. For this reason, it is necessary to pay
attention during the installation of the machine on its
foundations and in particular way during the
regulation of the feet.
It is necessary to verify that the foundation planes
have an optimal planarity to avoid torsion
deformations on motor chassis due to planarity errors,
when the motor is fixed to the floor.
After the machine has been aligned, shimmed and
firmly secured to the base, a dial indicator micrometer
oriented in the vertical direction shall be attached at
the mounting foot to be checked. The micrometer is
then zeroed the mounting bolt or bolts loosened at the
foot and the change in micrometer reading noted. If
the micrometer reading exceeds 0.05 mm (0.001 in),
the mounting requires cleaning or re-shimming. This
soft foot check shall be performed at each mounting
foot, with the other feet secured, until all micrometers
change readings are less than 0.05 mm (0.001 in). If
there are intermediate bases, this check shall be
performed at each interface between the machine and
the floor.
3. Preparation for installation
Prepare a set of steel sheet for shimming under the feet
of the motor. Possible adjustments require shim
thickness of 1 - 0.5 – 0.2 – 0.1 – 0.05 mm.
It is necessary to have at site:
jacking for vertical positioning and screws or jacks
for axial and horizontal adjustments.
dial indicator gauges and related attachments to
achieve precise alignment within the specified
tolerances (see relevant sheet).
a set of leveling screw (see Fig. 1) and similar
equipment.
4. Installing machines with bedplate (Fig. 1-3)
The following information describe the suggested
method for installing the machines. Other methods (i.e.
separate fixation of the bedplates) are possible.
Bedplates, fastening bolts, anchor bolts and leveling
elements are not usually supplied with the machine.
If this elements are part of the order, they will be
delivered as separate items.
4.1. The upper plane of the foundation must be clean
(possibly vacuum cleaned). The walls of the
grouting holes must have rough surface to allow a
good grip. Presence of oil or grease must be
removed by chipping away slices of the concrete
surface.
4.2. Insert the greased leveling screws into the motor
feet. Mount coupling hub to shaft extension. Wrap a
layer of tape around the upper part of the anchor
bolts (about 50 mm) to prevent this part from getting
stuck in the concrete.
