Project Number: 228730 WWTE SCADA Upgrades
Issue Date: August 2017 Nashua, NH
AC control, DC signal. Terminal blocks shall be the compression screw
type. Spring-clamp style terminals will not be accepted.
a. Discrete inputs and outputs (DI and DO) shall have 2 terminals per
point with adjacent terminal assignments. All active and spare
points shall be wired to terminal blocks.
b. Analog inputs/outputs (AI and AO) shall have a minimum of three
3 terminals per shielded pair. Three terminals shall be provided for
direct connection of powered, 4-wire loops. Four terminals shall be
provided for direct connection of loop powered, 2-wire loops. Five
terminals shall be provided for connection of analog loops
incorporating a local indicator or recorder. One terminal is for
shielded ground connections for cable pairs. Ground the shielded
signal cable at the PLC cabinet. All active and spare points shall be
wired to terminal blocks.
Wire and tube markers shall conform to Division 26 requirements.
d. Only one side of a terminal block row shall be used for internal
wiring. The field wiring side of the terminal shall not be within
6-inches of the side panel or adjacent terminal, or within 8-inches
of the bottom of the panel.
e. Whenever possible, the terminals for field wiring shall be located
to reduce the amount of routing through wireway necessary to
carry the field wiring to the termination point.
5. All wiring, internal to the panel and field wiring, shall be provided with a
service loop to allow for adjustment of the termination point in the future.
The service loop shall be no more than 4-5 inches, and shall be stored in
the associated wireway.
6. All wiring to hand switches, etc., which are live circuits independent of
the panel's normal circuit breaker protection, shall be clearly identified as
such.
7. All wiring shall be clearly tagged and color-coded in accordance with the
National Electric Code (NEC). All tag numbers and color-coding shall
correspond to the panel wiring diagrams prepared by the Engineer. All
power wiring, control wiring, grounding, and DC wiring shall utilize
different color insulation for each wiring system used. The color coding
scheme shall be:
a. Incoming 120 VAC Hot — Black
b. 120 VAC Hot Wiring (downstream of panel circuit breaker) — Red
120 VAC Neutral — White
a 0
Ground — Green
CONTROL SYSTEM EQUIPMENT PANELS AND RACKS
WOODARD & CURRAN 40 67 00-9
