30 November 1998
(d) Controller wiring.
(e) Supply fan and return fan starter wiring.
(f) Exhaust fan and pump starter wiring.
(g) HVAC control panel power wiring.
(h) Damper schedule
(I) Control system schematic
(j) Ladder diagram
(k) Equipment schedule
(l) Terminal block layout
(2) Some simple control systems do not require a control panel and would not require panel
drawings. DDC systems do not require a panel design, as these are available "off-the-shelf" from the
(3) The schematic will show control loop devices and other permanent indicating instrumentation
(such as pressure and draft gauges, thermometers, flow meters, and spare thermometer wells). The
indicating instrumentation is intended to permit a visual check on the operation of the HVAC control
(4) Control systems for HVAC often require connections to boiler control systems, chiller control
systems, variable speed drives, fire alarm and smoke detection systems, and EMCS. The schematic
and the ladder diagram will show the interface points between field installed HVAC control systems,
factory installed HVAC control systems, and other control systems.
(5) The ladder diagram will show the relationship of the devices within the HVAC control panel
and their relationship to HVAC equipment magnetic starters and other control panels.
(6) The equipment schedule will show the information that the vendor needs to:
Provide instrumentation of the calibrated ranges.
Select control valves and associated actuators.
Adjust the control system devices for sequencing operations.
Configure the controller parameters, such as setpoints and schedules.
Set the control system time clocks.
(7) The interior door layout will show the controllers, switches, pilot lights, pneumatic gauges,
current-to-pneumatic signal devices, and other door mounted devices.
(8) The back panel layout will show the location of all other panel mounted devices, and will
assign a back panel area for terminal blocks.
(9) The terminal block layout will show the location of specific terminal locations according to
their function, and the locations of spare terminals and unassigned spaces.
(10) The drawings will be those shown in chapter 4 of these instructions for the standard HVAC
control systems, with site-specific modifications and any additional control system loops required. The
number of contract drawings necessary to show each control system varies with the system size and
complexity. Most control systems in these instructions can be shown with the schematic, ladder diagram,
and equipment schedule on one drawing, and control panel details on two drawings.