Famco Danfoss Maneurop MT, Руководство пользователя, Страница: 120 / 294

Application guidelines
16
FRCC.PC.002.A5.22
Operating conditions
Operating limits
High pressure
A low-pressure (LP) safety switch must also be
used; deep vacuum operations will result in
failure. The minimum LP safety switch (loss of
charge switch) setting is 0 relative bar (0 bar
g). For systems without pump-down feature,
the LP safety switch must be either a manual lockout device or an automatic LP safety switch
wired into an electrical lockout circuit. LP switch
tolerance must not allow for vacuum operation
of the compressor. LP safety switch settings for
pump-down cycles with automatic reset are
listed in the following table.
A high-pressure (HP) safety switch is required to
shut down the compressor should the discharge
pressure exceed the values shown in the table
below. This switch can be set at lower values
depending on the application and ambient
conditions. It must be either located in a lockout circuit or associated with a manual reset device to
prevent cycling around the high pressure limit.
If a discharge valve is used, the HP switch must
be connected to the service valve gauge port,
which cannot be isolated.
Low pressure
NTZ – R404A / R507
Working pressure range, high side psig 191 - 402
Working pressure range, low side psig 0.7 - 48
Minimum low pressure safety switch setting psig 0
Minimum low pressure pump-down switch setting psig 3
Relief valve opening pressure difference (2 and 4 cycl) psig 435
Relief valve closing pressure difference psig 116