baxter ARENA - Venous Line Clamp; Venous Line Clamp System; VLC Driver Board

Arena Service Manual
10.7 VENOUS LINE CLAMP SYSTEM
The Venous Line Clamp (VLC) system will stop the flow of blood
in the venous line of the extracorporeal circuit in case of an
extracorporeal alarm (which could come from the Air Detector, the
Blood Leak Detector, or the Arterial or Venous Monitors). The
VLC system consists of the following elements:
•
•
Venous Line Clamp (linear or rotary)
VLC Driver Board.
Refer to Figures 10-4 and 10-7 for locations.
10.7.1 Venous Line Clamp
The VLC isolates the patient from the Instrument by blocking the
flow of blood from the extracorporeal circuit into the patient (see
Section 2.8.2). When power is applied to the line clamp, the
occlusion mechanism is pushed forward (linear) or rotated (rotary)
causing the VLC to unclamp. When power is removed, an internal
spring pulls or rotates the occlusion mechanism causing the VLC
to clamp.
Refer to Figure 10-6. When the VLC optical sensor detects that
the VLC is clamped, it will send a signal to the BP Controller
Board via the I/O Electronics Power Board and I/O Controller
Board. The BP Controller will then signal the BP Power Board to
stop the Blood Pump. This does not apply if using a Single Needle
procedure.
10.7.2 VLC Driver Board
The VLC Driver Board provides power to the linear or rotary
VLC. The VLC Driver Board receives 120 VAC from the
isolation transformer and coverts it to approximately 180 VDC.
When this voltage is applied to the magnetic coil within the VLC,
the VLC unclamps. Once the voltage is removed, the VLC clamps
due to an internal spring. When the VLC changes state from
clamped to unclamped, it draws the maximum current. The peak
current for the occurrence is 2.1 A (may vary by line clamp
resistance, inductance, and in-line AC voltage). The holding
current differs for the two available VLCs. The linear VLC
requires a nominal 330 mA and the rotary requires a nominal 480
mA. Selection pins are mounted on the VLC Driver Board
(bottom right hand corner, JP4). A two-pin jumper is provided
with each board. The position of the jumper depends on the type
of line clamp. The two top pins are for the rotary clamp, the two
10-12 157-1278-917 Rev A
April 2004