Accurex Temperature Interlock User manual
Product Specification
Temperature Interlock
International Mechanical Code (IMC) 2015 Section
507.1.1 compliant electrical package.
Provide Accurex, LLC temperature interlock electrical
package as shown on plans and in accordance with the
following specification:
The temperature interlock(s) consists of a time delay
relay, adjustable thermostat, junction box, fire proof/
leak proof threaded fitting (Evergreen Quik-Seal® and/
or Evergreen Compression Seal), and shall be a self-
contained unit or as part of another pre-engineered
electrical control package.
The temperature interlock package shall close a time
delay relay powering the fans when the set temperature
is reached at the thermostat. The interlock shall hold the
circuit closed upon fan switch being turned off until the
temperature at the sensor decreases below the set point
at which point the timed relay will begin a countdown.
Once the countdown has expired and as long as the
temperature has remained below the set point, the fans
shall shut down.
The temperature interlock package shall be constructed
by Accurex, LLC and operate in accordance with
International Mechanical Code.
Due to continuous research, Accurex, LLC reserves the
right to change specifications without notice.
WARNING
Electrical shock hazard. Can cause equipment
damage, personal injury or death. Service must only
be performed by personal that are knowledgeable in
the operation of the equipment being controlled.
CAUTION
Always disconnect power before working on or near
the product. Lock and tag the disconnect switch or
breaker to prevent accidental power up.
CAUTION
It is the responsibility of the installer to make sure both
electrical and gas appliances shut down in the event
of a fire or in the event of a power loss to the building
when this sequence is required by the authority having
jurisdiction.
General Safety Information
Only qualified personal should install this product.
Personnel should have a clear understanding of these
instructions and should be aware of general safety
precautions. Improper installation can result in electric
shock and other potential hazards.
1. Follow all local electrical and safety codes, as well as
the National Electrical Code (NEC) and latest edition
of the National Fire Protection Agency Standard for
Ventilation Control and Fire Protection of Commercial
Cooking Operations (NFPA 96). Follow the Canadian
Electrical Code (CEC) and ULC-S650 if installing this
product in Canada.
2. Do not allow the electrical components of this
product to come in contact with oil, grease, hot
surfaces, water, or chemicals.
3. Verify the site can supply the necessary power for
each fan and for the control panel.
Temperature Interlock 1
Installation, Operation and Maintenance Manual
Please read and save these instructions for future reference. Read carefully before attempting to assemble, install,
operate or maintain the product described. Protect yourself and others by observing all safety information. Failure
to comply with these instructions will result in voiding of the product warranty and may result in personal injury
and/or property damage.
Document 473592
Temperature Interlock
Table of Contents
Product Specification ........................1
General Safety Information ....................1
General Description ..........................2
Receiving and Handling.......................3
Installation
Control Box Mounting .....................3
Thermostat(s) - Hood Mounting ............3-4
Thermostat(s) - Duct Collar Mounting .........4
Electrical Connections
Fan Starters Provided by Others .............5
All Exhaust/Supply Fan Starters Provided in
Make-Up Air Unit (MUA) ..................6
Thermostat Connections ...................6
Calibration...............................7
Control Circuit Diagram .......................8
Testing ...................................9
Operation ..................................9
Troubleshooting ............................10
Maintenance ..............................10
Frequently Asked Questions ..................11
Replacement Parts .........................11
Codes and Standards Compliance .............11
Our Commitment ...........................12
General Description
Description
The temperature interlock is designed to automatically
start kitchen hood exhaust fans and keep them
running while heat is being generated from the cooking
appliances. Hood systems should always be manually
started before equipment is turned on. If the operator
fails to turn the fans on, the interlock will turn the fans
on once enough heat is detected. The package consists
of a time delay relay, adjustable thermostat, junction
box, and a UL Listed, liquid-tight fitting. The relay can
be contained in a stand alone box or can be added to a
pre-engineered fan control center.
Purpose
To meet IMC, an interlock between exhaust fans and
cooking equipment must be present for all Type I hood
systems. This product will utilize a thermostat in the
exhaust duct collar or in the capture area of the hood
to detect heat generated from cooking operations and
automatically activate the exhaust fans if not already
turned on.
Product Application
The temperature interlock can be used with Type I and
Type II hoods. It is not to be used in conjunction with
exhaust fire dampers. Accurex recommends using one
interlock per hood system (activates all fans linked to
systems simultaneously).
Performance Goals
To meet IMC, the fans need to activate not more than
15 minutes after the first appliance served by that hood
has been turned on. Ambient kitchen temperatures are
not the same in all commercial kitchens. Therefore, set
point adjustments may be necessary on the thermostat
to make sure the system meets this 15 minute
requirement.
Temperature Interlock2
Receiving and Unpacking
Receiving
Upon receiving the product, check to make sure all
items are accounted for by referencing the bill of lading
or packing list to ensure all items were received. Notify
the carrier if any damage is noticed. The carrier will
make notification on the delivery receipt acknowledging
any damage to the product. All damage should be
noted on all of the copies of the bill of lading which is
countersigned by the delivering carrier. If damaged upon
arrival, file a claim with the carrier. Any physical damage
to the unit after acceptance is not the responsibility of
the manufacturer.
Unpacking
Verify that all required parts and the correct quantity of
each item have been received. If any items are missing,
report shortages to your local representative to arrange
for obtaining missing parts.
Storage
If a temperature interlock must be stored prior to
installation, it must be protected from dirt and moisture.
Indoor storage is highly recommended.
Handling
Make sure the equipment does not suffer any heavy
vibration or knocks.
NOTE
Improper storage which results in damage to the unit
will void the warranty.
Control Box Mounting
Installation
Locate an area with enough space to mount the control
box and fasten to the wall. Avoid installing the control
box in environments with high magnetic and/or radio
frequency interference.
Hood Plan View
19.525 inches
(495.9 mm)
3 inch air space
(76.2 mm)
2 inch typical
(50.8 mm)
Exhaust Area
Supply Area
(optional)
Sensor Install
(cut out area)
2. Find a suitable
location for the sensor
in the flat space that
will not interfere with
the fire suppression nozzles
and that is not within
12inches (304.8 mm) of
any light fixtures. Cut a 11⁄8
to 1¼ inch (28.6 to 31.8 mm)
diameter hole in the flat spot of the capture tank.
3. Place the J-box plate inside the octagon extension
ring and place over the hole.
4. Disassemble the compression seal and place
through hole and J-box plate as shown. Tighten the
nut inside the octagon extension ring.
1. Locate the flat area(s) at the top interior of the hood
in front of the filters, towards the front of the hood.
Hood Surface
(28.6 to 31.8 mm)
NOTE
Control box may be factory mounted. If so, continue
to the next section.
NOTE
Thermostat sensor(s) may be factory installed. If so,
continue to the next section.
Thermostat(s) - Hood Mounting
Gasket
Compression Seal
PN 452614
Nut
Lock Washer
Octagon Extension
PN 830125
Junction Box Plate
PN 732396
Exploded View (Components)
Temperature Interlock 3
Gasket
1/2 inch Quik-Seal
PN 451168
Nut
Lock Washer
Octagon Extension
PN 830125
Junction Box Plate
PN 732396
Exploded View (Components)
2 inches
(50.8 mm)
Hood Exhaust Collar
(front side)
(28.6 to 31.8 mm)
5. Place the thermostat through compression seal
and tighten the compression fitting to 35 ft.-lbs.
(47.5Nm).
6. Wire the thermostat. Refer to Electrical Connections
section for instructions on wiring the thermostat.
7. Place octagon cover onto J-box and fasten it.
Thermostat(s) – Duct Collar Mounting
1. Locate the exhaust duct on top of the hood. Find
a spot to mount the thermostat where it will not
interfere with fire suppression nozzles or other items
installed in the ducts. If an exhaust fire damper
is present in the hood exhaust collar, it must be
removed prior to temperature sensor installation. A
11⁄8to 1¼ inch (28.6 to 31.8 mm) diameter hole must
be cut into the duct 2 inches (50.8 mm) above the
hood top.
2. Place the J-box plate inside the octagon extension
ring and place over the hole in the exhaust collar.
3. Disassemble the Quik-Seal fitting and place through
hole in duct collar and J-box plate as shown. Tighten
the nut inside the octagon extension ring.
4. Thread the thermostat into the Quik-Seal fitting until
secure.
5. Wire the thermostat. Refer to Electrical Connections
section for instructions on wiring the thermostat.
6. Place octagon cover onto J-box and fasten it.
Installation - continued
Temperature Interlock4
NOTE
All wiring of electrical equipment must be done to meet NEC and local codes.
NOTE
All field wire must be high temperature rated. All 115VAC field wiring (or higher) must be routed through hard or
flex conduit. All low voltage field wiring should be plenum rated if not routed through conduit. Field wiring should
not come in contact with the surface of the hood. To reduce the likelihood of electromagnetic disturbance, avoid
routing high and low voltage cables in the same cable conduit.
NOTE
Temperature interlock may be integrated into the kitchen fan control center (XFCC). The electrical information
below pertains to stand-alone temperature interlock packages only. For more details on wiring the XFCC, please
refer to the proper IOM which can be found on the Accurex website, www.accurex.com.
Electrical Connections
All Fan Starters Provided by Others
1. Wire 115 VAC power from non-shunted breaker to terminal blocks H1 (hot) and N1 (neutral) in temperature
interlock panel.
2. Wire fan switch (either provided in field, shipped loose for remote install, or provided on hood/hood utility cabinet)
to terminal blocks S1H and S1 in temperature interlock panel.
3. Wire AC voltage needed to activate fan starters (115 or 24 VAC) to terminal block CP1 (hot).
4. Wire one side of all exhaust
fan starter coils to terminal
block CP2.
5. Wire common (C) of
dedicated fire system
microswitch to terminal
block CP2.
6. Wire normally open (NO)
to fire system microswitch
mentioned in item 5 above
to terminal block CP1.
7. Wire normally close (NC)
of fire system microswitch
mentioned in item 5 above
to one side of all supply fan
starter coils.
8. Wire the other side of all
exhaust fan and supply fan
starter coils back to neutral.
9. Wire thermostats in parallel
and connect between
terminal blocks T1-A and
T1-B (see Thermostat(s)
Sensors section for details).
NOTE
CP1 and CP2 are dry contacts from the factory. The field
needs to wire AC power they want to use to activate their
fan starters to terminal block CP1. All exhaust fan starters
need to be wired between CP2 and a neutral. Contacts
used to make this connection on the time delay
relay are rated up to 125 VAC and 10 amps. Make
sure the control circuit does not exceed these ratings.
If exceeded, this can damage the contacts on the relay
which will require replacement.
T1-A
115 VAC INPUT
POWER (POWERS
TIME DELAY RELAY)
T1-B
H1
N1
HOT
NEUTRAL
TEMPERATURE CONTROL BOX
CP1 S1H
115 OR 24 VAC
CONTROL POWER
(POWER USED TO
PULL IN MOTOR
STARTER COILS)
HOT
NEUTRAL
S1 CP2
TOGGLE FAN
SWITCH
FIRE SYSTEM MICROSWITCH
(IN FIRE SUPPRESSION RELEASE)
EXHAUST FAN
STARTER COILS
TSTAT 1
SUPPLY FAN
STARTER COILS
(IF APPLICABLE) (IF APPLICABLE)
WIRE ALL THERMOSTATS IN PARALLEL
TSTAT 2 TSTAT 3
COM NO
NC
Temperature Interlock 5
T1-A
115 VAC INPUT
POWER (POWERS
TIME DELAY RELAY)
T1-B
H1
N1
HOT
NEUTRAL
TEMPERATURE CONTROL BOX
CP1 S1H S1 CP2
TOGGLE FAN
SWITCH
FIRE SYSTEM MICROSWITCH
(IN FIRE SUPPRESSION RELEASE)
H
G
R
MAKE-UP AIR UNIT
(EXHAUST FAN
STARTERS
FURNISHED IN
MAKE-UP AIR UNIT)
TSTAT 1
(IF APPLICABLE) (IF APPLICABLE)
WIRE ALL THERMOSTATS IN PARALLEL
TSTAT 2 TSTAT 3
COM NO
NC
All Exhaust/Supply Fan Starters Provided in Make-Up Air Unit (MUA)
1. Wire 115 VAC power from non-shunted breaker to terminal blocks H1 (hot) and N1 (neutral) in temperature
interlock panel.
2. Wire fan switch (either provided in field, shipped loose for remote install, or provided on hood/hood utility cabinet)
to terminal blocks S1H and S1 in temperature interlock panel.
3. Wire common (C) of dedicated fire system microswitch to terminal block CP2.
4. Wire normally open (NO) of fire system microswitch mentioned in item 3 above to terminal block CP1.
5. Run three (3) low voltage wires (18 gauge) from MUA unit control center down to temperature interlock panel.
a. Terminal block R in MUA connects to terminal block CP1 in temperature interlock panel.
b. Terminal block H in MUA connects to terminal block CP2 in temperature interlock panel.
c. Terminal block G in MUA connects to the normally closed (NC) of dedicated fire system microswitch.
6. Wire the thermostats in parallel and connect between terminal blocks T1-A and T1-B (see Thermostat(s) Sensors
section for details).
Electrical Connections - continued
Thermostat(s)
Unless already done by the factory, wire all thermostats in a parallel back to terminal blocks T1-A and T1-B in
temperature interlock panel using 14 gauge 90°C minimum conductors.
CAUTION
Do not connect temperature sensor in series with fan
power. Depending on motor amperage, this can cause
damage to the thermostat and potentially the fan motor.
Temperature Interlock6
Calibration
Thermostat is preset by factory to
95°F (35°C) and has a slow make
and break contact. It will make
contact on a temperature rise and
break contact on temperature
fall. The temperature set point
may have to be adjusted slightly
depending of both ambient
and cooking conditions. The
adjustment knob is located on
the back of the thermostat. Use a
small blade screwdriver to make the adjustments.
1. Turn counterclockwise to increase the temperature
set point, turn clockwise to decrease the
temperature set point.
2. Quarter revolution in either direction corresponds to
a 22.5°F (-5.3°C) adjustment. Be sure to make small
adjustments, about 1/16 of a turn (≈6°F) or less at
one time.
3. Do not exceed more than one-half revolution in either
direction.
4. Check system operation before making additional
adjustments.
Adjustment
Screw
Temperature Interlock 7
Control Circuit Diagram (Stand-Alone Package)
This is an example of a generic wiring diagram for standard control. It provides temperature interlock
function for two exhaust fans and one supply fan. (All starters provided by others, external to this control box).
S1H S1
TS1
6
12
TDR
NOC
T1-A
T1-B TS2
THERMOSTAT(S)
WIRED IN PARALLEL
BETWEEN T1-A & T1-B
383271 (OFF DELAY 1-100 MIN)
STB
N
ST
S
LT
G
FS
EF
SF
OL
C
OR - orange
YW - yellow
WT - white
RD - red
PR - purple
FIELD WIRING
BK - black
BL - blue
UNLESS SPECIFIED
BR - brown
FACTORY WIRING
Shunt Trip Breaker
Neutral
Starter
Switch
Light
Ground
Fire MicroSwitch
Exhaust Fan
Supply Fan
Overload
Contactor
TDR
TS1-12
Time Delay Relay
Temperature Sensor
LABEL DESCRIPTION
WIRE COLOR
ALL WIRING 90°C 14 GA.
USE MINIMUM
60° Copper Wire
FIELD WIRING:
S1
CP1
CP2
FS
FIELD WIRE FIRE SYSTEM
MICROSWITCH
NO NC
C
ST
TYP. EXHAUST
ST
TYP. EXHAUST
ST
TYP. SUPPLY
CONTROL INPUT: 24/115 VAC, 15AMPS FROM BREAKER
FIELD MOUNTED SWITCH
FIELD WIRING TO SWITCH REQUIRED
RD RD
CONTROL INPUT: 115VAC, 15AMPS FROM BREAKER
H1
L1
N1
N
BK
G
WT
BK
YW
Temperature Interlock8
Operation
1. Turn fans on and off using the fan switch. It is normal
for the fans to remain running after the switch is
turned off. The exhaust thermostat will open after
heat is no longer present under the hood which will
activate the timed relay to begin its countdown.
Once time has expired, fans will shut down. The
timed relay is adjustable from 1-100 minutes. The
recommended time delay setting is approximately
20minutes.
2. In the event that the cooking equipment is started
without turning the fans on manually, the fans will
turn on automatically and remain running with the
presence of heat under the hood. The exhaust
thermostat will open after heat is no longer present
under the hood which will activate the timed relay to
begin its countdown. Once time has expired, fans
will shut down.
Testing
1. Turn fan switch on, then off to ensure proper fan
operation before cooking equipment is started. Once
this is verified, testing can proceed.
2. For testing only, locate the time delay relay. Turn the
time adjustment knob counterclockwise to the first
mark in order to expedite the testing process. Make
a note as to where the time relay was originally set.
3. Heat up cooking equipment with fans off. Once the
temperature reaches the set point of the thermostat
the fans will start, preferably within 5 to 10minutes.
If the fans take more than 15 minutes to start,
decrease the temperature set point by turning the
adjustment screw 1/16 turn clockwise. Do not apply
direct flame to the thermostat
4. If an adjustment was made in Step 3, repeat now.
5. After verification of fan start-up, shut down cooking
equipment. The fan switch should still be in the off
position. Once cooking equipment has cooled, the
thermostat will open triggering the timer function in
the time delay relay to begin. Once time has expired,
the fans will shut down. Thermostat operation can
be verified by checking voltage (115 VAC) between
terminal blocks T1-B and N1 in the control panel.
6. Once proper operation has been verified, set
the dial on the timed relay to its original setting
(approximately 20 minute delay).
CAUTION
The thermostats should never be exposed to direct
flame. This can cause permanent damage to the
thermostat.
NOTE
During testing, if fans do not start automatically in
the first 15 minutes of cooking equipment activation,
manually start fans to avoid accidental fire system
dump due to heat build-up.
Temperature Interlock 9
Troubleshooting
Fans do not turn on automatically upon cooking
equipment activation.
• Check wiring to control panel. Thermostats must
be wired in parallel.
• Temperature set point to high, decrease set point
• No power to fans, check breakers/starters/relays
Fans do not shut off.
• Fan switch must be in the off position
• Cooking equipment hot, wait for it to cool
• Temperature set point too low, increase set point
• Check control circuit (fan starter) wiring
• Time delay too great, turn down timed relay
Fans do not turn on quick enough.
• Decrease temperature set point
Maintenance
Daily
Clean thermostat with cloth and degreaser. Keep clean
for best performance. (Can clean weekly depending
upon grease accumulation).
Weekly
Dependant on grease production and grease filter type,
clean thermostat.
Seasonal
May have to change temperature setting on back of
thermostat if ambient kitchen temperatures fluctuate
between summer and winter seasons.
Whom to call
Contact your local Accurex representative.
What to have ready for the call
Sales order, serial number and description of product.
Sales Order Number ________________________
Serial Number ______________________________
Temperature Interlock10
Frequently Asked Questions
What temperature is the thermostat set from the
factory?
95º Fahrenheit.
Will the temperature interlock automatically start/
stop the fans?
When connected properly to fan starters the
temperature interlock will automatically control
the fans without input from the user. However, it is
intended to be used as a back-up to manual control.
May I connect the power going to my fan directly
through the control box?
No, the control box should only use control voltage
only (24-115 VAC), and a separate 115 VAC power
source is required to run the temperature interlock
controls. Accurex recommends the use of starters
sized for each fan.
What is the purpose of the timed relay in the control
box?
The timed relay is used to delay the shut down
of the fans to prevent fan on/off cycling while the
temperature in the exhaust duct can reach steady
state. Without the delay, cycling could occur both on
startup or shutdown of cooking equipment. The delay
is typically set at 20 minutes.
Can I use one control box for multiple hood systems?
This can be done, however, it is not recommended.
Any one of the thermostats would turn on all hoods
running on that control box. It is better to have one
hood/fan per control box, plus a significant energy
savings can be obtained if one or more of the hoods
is not in operation.
Can I still turn my fan on and off?
Yes, the temperature interlock is designed to be
operated with a typical on/off switch. The fan may not
turn off immediately after turning the fan switch off, it
will sense when the cooking operations have cooled
and then turn off.
Replacement Parts
Part
Number Description
383923 Thermostat, Vulcan
1C2B9 5/8-inch Type C
451168 Evergreen Quik-Seal, 1/2-inch
#171 (1-1/8 inch hole size)
830125 Extension, Octagon (drilled)
SC55151-1/2 (380928)
380926 Cover, Octagon Box
SC#54-C-1RACO 722
732396 J-Box Plate
384905 Terminal Block, Single Pole,
DIN-RAIL MT, ABB ZS6
384908 Jumper, DIN-RAIL
Terminal Block 2 Pole ABB JB6-2
383271 Time Delay Relay SSAC
#KRDB424 SPST 1-100 min.
452614 Evergreen Compression Seal,
5/8-inch, #302
Codes and Standards Compliance
• UL 710
• National Fire Protection Association (NFPA 96)
• International Mechanical Code (IMC)
Temperature Interlock 11
12
Our Commitment
473592 • Temperature Interlock, Rev. 3, January 2017 © 2017 Accurex, LLC12
As a result of our commitment to continuous improvement, Accurex reserves the right to change specifications
without notice.
Product warranties can be found online at accurex.com, either on the specific product page or in the Warranty
section of the website at Accurex.com/Resources/Warranty.
Our Commitment
P.O. Box 410 Schofield, WI 54476
Phone: 800.333.1400 • Fax: 715.241.6191
Parts: 800.355.5354 • accurex.com
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