VARIABLE FREQUENCY DRIVES
KITCHENER – BUS FACILITY
CONTRACT NO. IT-2015-BI-048
PART 1
1.1
1.2
1.3
GENERAL
General Conditions
.1
Read and be governed by Conditions of the Contract.
.2
Comply with Mechanical General Conditions, Section 15010.
Description of Work
.1
This specification defines the general requirements for Variable Frequency Drives
(VFD) for motor speed control of mechanical equipment.
.2
Each mechanical equipment supplier shall provide the required variable frequency
drive as indicated on drawings, equipment schedules and specifications.
.3
Acceptable VFD manufacturers include ABB, AC Tech, Allen Bradley, Danfoss,
Siemens, Schneider Electric. All VFD’s shall be factory assembled units.
Standards
All VFD’s shall be CSA and ULC approved.
.1
1.4
Submittals
.1
PART 2
2.1
SECTION 15860
PAGE 1 OF 8
APRIL 2016
Provide catalogue, technical data, outline dimensions, shipping section
dimensions, weight, control schematics, external connection diagram showing
function and identification of all terminals requiring field connections for power
and building automation system.
PRODUCTS
Design
.1
Manufacturer shall submit a computerized harmonics analysis of the facility
system based on the most recent single line diagram. Analysis shall illustrate the
effect of VFD's on system harmonics.
.2
Manufacturer shall provide input line reactors and/ or line filters required to
reduce the total harmonic distortion (THD) to 5% at the point of common
coupling or 3% at each VFD input where the analysis has shown that the
incremental effect of the addition of the VFD's would cause the THD to exceed
these values as per IEEE 519-1992.
VARIABLE FREQUENCY DRIVES
KITCHENER – BUS FACILITY
CONTRACT NO. IT-2015-BI-048
2.2
SECTION 15860
PAGE 2 OF 8
APRIL 2016
.3
The VFD shall be of the fully digital pulse width modulated (PWM) type utilizing
insulated gate bipolar transistors (IGBT's) in the inverter section of the VFD. The
VFD shall accept AC line voltage variation of +10%, -15%. No transformers shall
be used on either the input or output of the VFD.
.4
For indoor locations or within weatherproof outdoor cabinets, provide NEMA 1
type enclosure. NEMA 1 enclosures shall have a fan cooled enclosure with
sprinkler proof hood. For outside locations, provide VFD with NEMA 4X type
enclosure.
.5
Provide incoming, horsepower rated, disconnect switch with an operating
mechanism, door interlocked and padlockable in the open position.
.6
Provide input line fuses coordinated with the VFD’s electronic protection circuits
so as not to blow under normal output faults such as overcurrent, short circuit and
ground fault.
.7
Provide output filters on all 460 & 575 volt VFD’s to limit the dv/dt to 1,000 volts,
0.5 micro seconds at the motor terminals.
.8
Provide a terminal block within the VFD for field termination of line side wiring.
.9
Equipment supplier shall specify motors with a minimum of Class F insulation.
Supplied motor shall be rated for inverter duty.
.10
Variable frequency drive control and integration: Where VFD are provided on
equipment (pumps, HRV’s) for control by the BAS, provide hardwired start/stop
DO, control AO, Modbus or BACnet integration of VFD data.
Protection
.1
Provide the following VFD protection features as a minimum:
(a)
Line over and under voltage protection.
(b)
Phase loss and unbalance protection.
(c)
Short circuit protection for line to line and line to ground faults.
(d)
Electronic instantaneous overcurrent protection.
(e)
Current limit, adjustable between 0% and 110% for 30 minutes.
(f)
The VFD shall have a continuous duty service factor of 100% of rated
output current with 12t overload protection rating of 150% for 1 minute.
(g)
Internal over temperature protection.
VARIABLE FREQUENCY DRIVES
KITCHENER – BUS FACILITY
CONTRACT NO. IT-2015-BI-048
(h)
2.3
Electronic motor stall protection to trip the VFD off should a motor
overload or stall occur.
Environment
.1
2.4
SECTION 15860
PAGE 3 OF 8
APRIL 2016
The VFD shall have the following minimum environmental tolerances:
(a)
Ambient temperature range of O°C to 40°C. Units located in non-heated
areas shall be provided with thermostatically controlled heater weather
enclosure.
(b)
Maximum humidity of 95% non-condensing.
(c)
Maximum altitude of 1,000m for rated output.
Performance
.1
The VFD shall have the following performance features as a minimum:
(a)
Minimum efficiency of 97% at maximum load and speed.
(b)
Minimum line side displacement power factor of 0.98 at all speeds and
loads.
(c)
Adjustable minimum and maximum motor frequency\cy of 0 to 360 Hz.
(d)
Vector Control mode without tachometer feedback.
(e)
Separately adjustable acceleration and deceleration ramps from 0 to 3/600
seconds with damping and smoothing parameters for (0% to 100% speed).
(f)
DC Injection Braking.
(g)
Automatic restart after an inverter fault trip. The VFD shall attempt to
restart automatically 5 times with Lock-Out after the third attempt if a
restart has not occurred.
(h)
The VFD shall restart the motor at the speed at which it is rotating and
then re- accelerate to the speed called for by the speed reference signal.
(i)
Capable of running without a motor connected for setup and testing.
(j)
Capable of accepting the opening of a remote motor disconnect while
running without causing damage to the VFD.
(k)
Auto restart after power outage.
VARIABLE FREQUENCY DRIVES
KITCHENER – BUS FACILITY
CONTRACT NO. IT-2015-BI-048
2.5
(l)
Skip frequency reject point to prevent the fan/ pump from operating at a
resonant speed. Adjustable centre frequency with a band width of 0 -10
Hz.
(m)
Automatic/manual signal follower for 4-20 mA, 0-20mA, 0-10 VDC or 210 VDC reference.
Operator Interface
.1
Provide a door mounted keypad with a 32 character Alpha-numeric high
resolution display to allow the operations personnel to set up and monitor the
VFD parameters, observe output speed, load or other programmable values and
monitor status and fault information, complete with tactile keys and backlit
display.
.2
Provide maintenance monitoring to display the time since starting, total elapsed
run time and total KWH. Also provide maintenance target alarm to alert the
operator with a displayed message.
.3
Provide the following control functions on the door mounted keypad:
.4
2.6
SECTION 15860
PAGE 4 OF 8
APRIL 2016
(a)
Run (Manual Mode)
(b)
Stop (Auto and Manual Mode)
(c)
Parameterisation button (to toggle between parameters)
Provide a selectable display to observe the following parameters:
(a)
Frequency
(b)
Frequency Setpoint 3. Motor Current
(c)
DC-Link Voltage
(d)
Motor Torque (% nominal) 6. Motor RPM
Fault Information
.1
Provide fault diagnostics to simplify troubleshooting. In the event of a fault
condition, the display shall indicate the nature of the fault, Including:
(a)
Overvoltage
(b)
Undervoltage
(c)
Overcurrent
VARIABLE FREQUENCY DRIVES
KITCHENER – BUS FACILITY
CONTRACT NO. IT-2015-BI-048
2.7
2.8
(d)
Overload
(e)
Overheating of Motor (monitoring with PTC)
(f)
Inverter over temperature
(g)
Main phase missing (for 3 phase units)
SECTION 15860
PAGE 5 OF 8
APRIL 2016
Bypass
.1
Provide components and circuitry necessary to safely bypass the motor from the
VFD to line, or from the line to the VFD at zero speed.
.2
Provide a door interlocked input circuit breaker to ensure positive shutdown of all
input power to both the VFD and bypass. Motor protection to be provided in both
modes of operation by a common thermal motor overload relay.
.3
Provide mechanically interlocked contactors on the output of the VFD and in the
bypass circuit.
.4
The entire bypass assembly, as well as all associated auxiliaries, shall be a
modular design for single piece installation.
.5
Enclosure door to include an inverter/bypass selector switch with indicator lights
for each mode of operation.
Communication and Control
.1
Provide the following to interface with the Energy Management Control System
(EMCS):
(a)
Dry contact closure from EMCS for run Command (Auto Mode).
(b)
4-20 mA (0-20 mA, 0-10 VDC, 2-10 VDC signal from EMCS for speed
control (Auto Mode).
(c)
Dry contact (N.O.) output to EMCS to indicate:
i.
ii.
Inverter Fault
Inverter Running
(d)
0-20 mA or 4-20 mA analog output to EMCS, proportional to 0-100%
speed or load.
(e)
Terminal for interlocking of up to 5 external interlocks e.g. Firestat,
Freezestat, etc.
VARIABLE FREQUENCY DRIVES
KITCHENER – BUS FACILITY
CONTRACT NO. IT-2015-BI-048
.2
Provide serial communications interface and software to permit remote
monitoring and modification of all VFD parameters. Interface shall have the
following features:
(a)
.3
2.9
2.10
SECTION 15860
PAGE 6 OF 8
APRIL 2016
Connection capable of RS-485 communications standards.
Provide a process controller with the following feature as a minimum:
(a)
Input: Field process signal (temperature, pressure, etc.)
(b)
Output: 4-20 mA or 0-10 V speed reference to the VFD.
(c)
Programmable proportional, integral and derivative gains.
(d)
Operator adjustable process setpoint.
System Operation
.1
If "Manual" mode is selected the VFD/motor will start when the run key is
depressed. The speed will be controlled by depressing the Accelerate or
Decelerate keys on the keypad or by the direct speed set mode.
.2
If II Auto" mode is selected the VFD / motor will start when a contact closure run
command is received from the EMCS. The speed will be controlled by a speed
reference signal from the EMCS.
.3
In the event of a power outage the VFD shall automatically restart when the
power returns provided the run command is maintained.
.4
In the event of an inverter fault trip the VFD shall attempt to restart automatically
up to maximum of 5 attempts. If, after 5 attempts, restart does not occur, the VFD
shall lock out
VFD Pump System Controls
.1
The drive manufacturer shall provide necessary controls to operate each VFD and
maintain system hydronic or air pressure. The controls and/or VFD shall monitor
pressure differential in the water loop or duct system and operate to maintain
design pressure and flow requirements.
.2
Each controller shall provide the following minimum outputs to the BAS:
(a)
General Alarm (VFD failure, system pressure failure)
(b)
Pump(s) status
(c)
Fan(s) status
VARIABLE FREQUENCY DRIVES
KITCHENER – BUS FACILITY
CONTRACT NO. IT-2015-BI-048
.3
PART 3
3.1
3.2
SECTION 15860
PAGE 7 OF 8
APRIL 2016
The controller shall accept the following minimum input signals from the BAS:

On/Off

Set point
EXECUTION
Installation
.1
Install each VFD in accordance with manufacturer's recommendations and local,
provincial and national safety codes.
.2
Coordinate the VFD installation and wiring with section 15900 and Division 16.
.3
Arrange for on-site commissioning start-up of the VFDs by a factory authorized
technician. Allow for additional VFD technician site time to coordinate the
requirements of the commissioning plan.
.4
Install the pressure transducers in piping and pressure switches in ductwork as
required by the manufacturer. Provide all necessary field control wiring between
VFDs, control panels and sensors.
.5
Provide three complete sets of service and maintenance manuals including wiring
and connection diagrams for VFD’s. Include in these manuals, a paper copy and
one (1) electronic copy of the VFD baseline parameters ready for uploading for
future use by owner.
Variable frequency drive testing and acceptance
.1
Submit VFD performance checklist to Commissioning Authority for review prior
to start of on-site VFD commissioning.
.2
Perform site VFD inspection of all required connections and installation
requirements before starting each VFD unit.
.3
Operate each VFD through standard range of speed modulation and verify input
and output signals to BAS.
.4
Each VFD shall be operated for minimum of 10 hours of logged trouble-free
operation including connection to building automation system for same 10 hour
period. This VFD operation shall be witnessed by the Commissioning Authority
and the Consultant.
.5
Submit completed VFD checklist for each unit to verify operation of VFD.
VARIABLE FREQUENCY DRIVES
KITCHENER – BUS FACILITY
SECTION 15860
PAGE 8 OF 8
APRIL 2016
CONTRACT NO. IT-2015-BI-048
.6
Acceptance of VFD units shall occur after the above tests and checklists have
been received by the Commissioning Authority and the Consultant.
End of Section