2. INSTALLATION
Page 9
© 2009 DH Instruments, a Fluke Company
2.3.5
CONNECTING PNEUMATIC POWER (DRIVE PORT)
Using a pressure connecting hose or tube of appropriate pressure rating, connect drive air supply
to the
DRIVE
port on the rear panel of PPCH. It is important to proper PPCH pressure control
that the supply connection not excessively restrict flow. The tube should have an ID of at least 3
mm (1/8 in.) and not be more than 2 m (6 ft) long. Generally, a 3 mm ID tube has OD of at least
6.35 mm (1/4 in.). The
DRIVE
port connection is
1/8 in. NPT female
.
The drive air supply is regulated internally by PPCH. Drive air requirements for the different
PPCH models are listed in Table 3.
Table 3.
Drive air requirements
MODEL
MINIMUM DRIVE AIR
PRESSURE
MAXIMUM DRIVE AIR
PRESSURE
MINIMUM
UNINTERRUPTED
FLOW
PPCH-70M
500 kPa (75 psi)
PPCH-100M
700 kPa (100 psi)
330 l/m (10 cfm)
PPCH-140M
500 kPa (75 psi)
PPCH-200M
700 kPa (100 psi)
850 kPa (120 psi)
450 l/m (15 cfm)
2.3.6
SETTING UP AND FILLING THE FLUID RESERVOIR
The PPCH fluid reservoir holds the fluid that supplies PPCH’s hydropneumatic pump and
returns from its exhaust valve.
PPCH has an internal reservoir with a capacity of 300 cc that is filled from and whose level can
be viewed on the rear panel of the instrument. If greater capacity and/or remote reservoir filling
and level viewing are needed, external reservoir (part number 402102) may be installed.
See Section 2.3.6.1 to set up and fill the internal reservoir.
See Section 2.3.6.2 to set up and fill an external reservoir.
Take care not to let the PPCH reservoir become empty. Operating PPCH with an empty
reservoir will cause the hydropneumatic pump to draw air and lose its prime. A pump that has
lost its prime must be reprimed using a special procedure (see Section 5.10.1). PPCH has a low
fluid level warning displayed on the front panel that can be also checked by remote command (see
Section 3.5.7.3).
The system connected to the TEST port is connected to the reservoir when the PPCH is
vented ([VENT] LED ON). If there is an open point in the system below the fluid level in the
reservoir, liquid will run from the reservoir and out of the open point.
2.3.6.1
INTERNAL RESERVOIR
The PPCH is shipped with its internal reservoir filled with PPCH’s working fluid.
To operate without an external reservoir, the internal reservoir attachments must
be installed on the PPCH rear panel. These are included with the PPCH
accessories (see Table 2).
