Siemens Servo Ventilator 300, Service Manual

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2
Servo Ventilator 300/300A Description of functions
E382 E380E 061 01 03 01 Siemens-Elema AB 77
N77
N78
300-A21X
Note regarding the +24 V
PO
; At each of
these pins at N77 and N78 it is allowed to
take out a maximum of 3 A. However, the
total current from these pins is not allowed
to be more than 4 A alltogether.
As indicated by the signal name, all control
signals are buffered which makes each
output pin short-circuit proof.
The power 24 V
PO
at N77 and N78
is disconnected if:
• The ventilator runs in internal battery
mode
• +24 V
PO
is short circuited
• The power section is overheated, approx.
48°C (118°F).
The power supply (+24 V
PO
) is automatically
reconnected when conditions return to
normal.
21 Power supply
The power supply, as described below, is all
included in PC 1618.
This description refers to PC 1618D. Some
functional deviations in older versions of
PC 1618 are also described.
Even when the mode selector is set to
Ventilator Off, there is still live current on
PC 1618:
• +5 V and +24 V if the power source is
Mains or an External battery
• +24 V
LOW POWER REG
if the power source
is the Internal battery.
Always disconnect mains power supply as
well as external and internal batteries before
performing any service intervention on the
power section.
21.1 Auxiliary outputs
There are two
AUXILIARY OUTPUTS
on the
power section casing, one 9-pin connector
(N77) and one 15-pin connector (N78).
Pin configuration and signal names can be
found in chapter "
8. Diagrams ".
Only accessories, supplies or auxiliary
equipment listed in Siemens-Elema catalogs
(”Products and accessories” Order No.
90 34 562 E323E and ”Spare and exchange
parts” Order No. 90 34 570 E323E) must be
connected to or used in conjunction with the
ventilator.
Warning: Use of accessories and auxiliary
equipment other than those specified in
these catalogs may degrade safety and
performance of the ventilator.