IBM System/370 145 Reference Summary page 108

a
POWER-ON SEQUENCE
Initial power-on sequence on the 3145 requires 208 vac
three-phase 60 Hz 100 amp service. Assuming all AC
CBs are made, and there are no thermals or circuit
protectors tripped, the following write-up is a sequential
description of a normal power-on sequence.
Initial Power-On Sequence
Action
Result Diagram Coordinate
1. Phase rotation input Pick K1 Not Shown
correct
2. K 1 points and EPO Pick K4
J1
okay
K4 contacts supply
+24vdc to Seq Circuits
M1
3. +24vdc and all 1/0 Pick K5-9
J1
group EPO okay (For
Initial power K11,
which 1s a reed relay,
MG check must be
picked by depressing
either the console
power-off key or the
check reset key.) Pick K11
K7
(Circuit is through
diode 85 CK reset
E5
console power Off)
03
The +24vdc to the K 11
pick coil is fed through
a K60 n/c point. K60
is the overvoltage
detect relay and should
be down.
K60 n/c L7
4. K 11 and all thermals
and auxiliary CB con-
tacts not tripped will
satisfy the inputs to
the SL T card located
at (HQ). This will per-
mit the pick of K 12.
KB
5. Depress the power-on POW Key F4
key Pick K14
K4
6. K14 points (G5) Pick K15 J6
9.6