5 check air gap, 6 release / voltage, 7 readjustment of air gap – Lenze MDxMA-MHxMA-MFxMA-MDERA-MHERA Three-phase AC motors User Manual
Page 49: Check air gap, Release / voltage, Readjustment of air gap

Maintenance/repair
Maintenance operations
Check air gap
l
49
BA 33.0005−EN 2.0
8.3.5
Check air gap
1. Check the air gap "s
Lü
" near the fixing screws between armature plate and stator
using a feeler gauge (
^ 51).
2. Compare the measured air gap with the maximum permissible air gap "s
Lümax.
"
(
^ 51).
3. If necessary, adjust the air gap to "s
Lürated
" (
^ 49).
8.3.6
Release / voltage
}
Danger!
The rotating rotor must not be touched.
{
Danger!
Live connections must not be touched.
1. Observe the brake’s function while the drive is being operated. The armature plate
must be tightened and the rotor must move free of residual torque.
2. Measure the DC voltage on the brake.
– The DC voltage measured after the overexcitation time (
, operating instructions
BFK 458, bridge half−wave rectifier) must equal the voltage for the holding. A
deviation of up to ±10 % is permissible.
8.3.7
Readjustment of air gap
}
Danger!
The brake must be free of residual torque.
(
Stop!
Observe for the flange version when it is fixed with additional screws:
Behind the threaded holes for the screws in the flange there must be clearing
holes in the endshield. Without clearing holes the minimum rotor thickness
cannot be used. Under no circumstances may the screws be pressed against
the endshield.
2. Screw the threaded sleeves into the stator by using a spanner.
1
/
6
revolution reduces
the air gap by approx. 0.15 mm.
3. Tighten screws, for torques (
¶ 51).
4. Check the air gap "s
Lü
" near the screws using a feeler gauge, "s
Lürated
" (
¶ 51).
5. If the difference between the measured air gap and "s
Lürated
" is too large, repeat the
readjustment.