Dynalco SST-2400H Speed Switch/Transmitter - Manual (Page 12)

Mounting the unit
The SST-2000A/H is installed using standard hand tools. It is generally mounted
in a panel or enclosure using standard practices.
About Electrical Connections
Internal Commons, Isolation
Signal input (low side, terminal 6) is common to the auxiliary output (low side,
terminal 7), to the dc supply (terminal 4), and to the main proportional output
low side (terminal 9). Relay contacts are always isolated
When powered with ac: all circuitry is isolated from the power line by the built-in
supply transformer
When powered with dc: the transmitter output is not isolated from the dc power
source. Any load driven by the transmitter (i.e. recorder, controller, etc.) must
have the same common as the negative side of the dc supply. Install a current
loop isolator between the 4–20mA output and the load if the load does not
reference the same common as the SST-2000.
10
Chapter 2
Install a current loop isolator between the 4–20mA output
and the load if the load does not reference the same
common as the SST-2000A/H.
WARNING: AVOID DAMAGE WHEN DC-POWERED
Fig. 2-1 Electrical
Connection Drawing.
Use shielded cable:
connect ungrounded
shield to terminal 4.
Route power line and
relay connections
separate from signal
meter and reset lines
to prevent electrical
noise interference.
Terminals 4, 6, 7, and
9 are internally tied
together to circuit
common unless unit
has signal isolation
transformer. In that
case, terminal 6 is
isolated.