Fenwal 35-70 Series User manual

F-35-70
November 2015
FEATURES
• Safe start with DETECT-A-FLAME®flame sensing
technology
• Custom pre-purge and inter-purge timings
• Single or three trials for ignition
•SystemdiagnosticLED
• Flame current test points
• Local or remote flame sensing
•Automaticreset
• Alarm output (normally closed contact)
• Open board, potted or enclosure
• Polarity insensitive flame sensing
APPLICATIONS
• Commercial cooking
• Crop dryers
• Infrared burners
• Construction and agriculture heaters
• Other gas-fired appliances
DESCRIPTION
The 35-70 is a 120 VAC direct spark ignition (DSI) control
designed for use in all types of gas-fired appliances. The control
uses a microprocessor circuit to provide precise, repeatable
timing and operating sequences. On-board diagnostics with LED
output makes troubleshooting easy and ensures safe and
efficient operation.
Export Information (USA)
Jurisdiction: EAR
ECCN: EAR99
Agency Certifications
SPECIFICATIONS
Recognized under the UL component program, UL
372. Software certified to ANSI/UL 1998. UL File
MH8817
Design Certified to ANSI Z21.20,
CAN/CSA C22.2 No. 199-M89
FM Approved as both an ignition device and a flame
safeguard. Restricted to single try models without 1
hour reset. TFI time must be 15 seconds or less.
Input Power 102 to 138 VAC, 50/60 Hz
Input Current 350 mA @120 VAC with gas valve
relay energized (control only)
Gas Valve 1.5A max @ 120 VAC
Operating Temperature -40°F to +175°F
(-40°C to +80°C)
Storage Temperature -40°F to +185°F
(-40°C to +85°C)
Flame Sensitivity 1.0 µA minimum
Flame Failure Response 0.8 seconds maximum
Flame Detector Self-check
Rate
Once per second minimum
Gas Types Natural, LP, or manufactured
Spark Rate:
Remote
Local
50/60 sparks/sec
25/30 sparks/sec
Size (LxWxH)
with enclosure
5.11 x 3.55 x 2.00 inches
(12.98 x 9.02 x 5.08 cm)
Moisture Resistance Conformal coated to operate non-
condensing to 95% R.H. Module
should not be exposed to water
Ingress Protection Not rated, protection provided by
appliance in which it is installed
Tries for Ignition One or three try versions available
Trial for Ignition Periods 4, 7, 10, 15 seconds available
Pre-purge and Inter-purge
Timings
0, 5, 15 or 30 seconds available
SERIES 35-70
120 VAC Microprocessor-Based
Direct Spark Ignition Control
R

Effective: November 2015
2 F-35-70
SEQUENCE OF OPERATION / FLAME
RECOVERY / SAFETY LOCKOUT
Start Up - Heat Mode
When a call for heat is received from the thermostat supplying
120VAC to L1, the control will reset, perform a self-check
routine, flash the diagnostic LED and begin a pre-purge delay.
Following the pre-purge period, the gas valve is energized and
sparking commences for the Trial For Ignition (TFI) period.
When flame is detected during the TFI, the sparking process is
terminated and the gas valve remains energized. The thermostat
and burner flame are constantly monitored to assure proper
system operation. When the thermostat is satisfied and the
demand for heat ends, the gas valve is immediately de-
energized.
Failure to Light - Lockout
SINGLE TRIAL MODEL
Should the burner fail to light, or a flame is not detected during
the TFI period, the gas valve will de-energize and the control will
go into lockout. The LED will indicate the fault code for ignition
lockout.
MULTI TRIAL MODEL
Should the burner fail to light or the flame is not detected during
the TFI period, the gas valve will de-energize. The control will
then go through an inter-purge delay before an additional
ignition attempt. The control attempts two additional ignition
trials before de-energizing the gas valve and entering lockout.
The LED will indicate the fault code for ignition lockout.
FLAME FAILURE - RE-IGNITION MODE
If the established flame signal is lost while the burner is
operating, the control will respond within 0.8 seconds by
immediately energizing the H.V. spark for the TFI period in an
attempt to relight the flame. If the burner does not light within
the TFI, the gas valve will immediately de-energize and single try
models will enter lockout. On multi-try models, a new TFI
sequence will begin after an inter-purge delay. Multi-try models
perform two additional attempts to light the burner before de-
energizing the gas valve and entering lockout. If the burner
relights, normal operation resumes.
FLAME FAILURE-RECYCLE MODE
With the “Recycle After Loss of Flame" option, upon loss of
flame, the gas valve is de-energized and the control proceeds to
inter-purge before attempting to relight the flame. Multi-try
models permit three tries for ignition including inter-purges. If
the burner relights, normal operation resumes. If the burner
does not relight, the control will enter lockout.
Lockout Recovery
Recovery from lockout requires a manual reset by either
resetting the thermostat, or removing 120 VAC for a period of 5
seconds. On models with automatic reset, if the thermostat is
still calling for heat after one hour, then the control will
automatically reset and attempt to ignite the burner.

Effective: November 2015
F-35-70 3
MOUNTING AND WIRING
The Series 35-70 control is not position sensitive and can be
mounted vertically or horizontally. The control may be mounted
on any surface and fastened with #6 sheet metal screws. Secure
the control in an area that will experience a minimum of
vibration and remain below the maximum ambient temperature
of 80°C (175°F).
All connections should be made with UL Approved, 105°C rated,
18 gauge, stranded, .054” thick insulated wire. Refer to the
appropriate wiring diagram when connecting the 35-70 to other
components in the system.
Wiring Diagrams - 35-70
Figure 1. Local Sense
Figure 2. Remote Sense
Figure 3. Multi-Pin Layout
CAUTION
All wiring must be performed in accordance with
both local and national electrical codes.
CAUTION
Label all wires prior to disconnection when
servicing controls. Wiring errors may cause
improper and dangerous operation. A functional
checkout of a replacement control should always
be performed.
WARNING
This product uses voltages of shock hazard
potential. Wiring and initial operation must be
performed by a qualified service technician.
WARNING
Operation outside specifications could result in
failure of the Fenwal product and other
equipment with potential for injury to people and
property.
Terminal Designations
Terminal Description
Multi-Pin
Connector
P/N: TE 1-644615-1
Quick
Connect
(inch)
NC Alarm 11 1/4”
V1 Valve Power 10 3/16”
L2 120 VAC (Neutral) 8 3/16”
V2 Valve Neutral 7 3/16”
L1 120 VAC Input (Hot) 6 1/4”
B. GND Burner Ground 2 3/16”
S1 Remote Flame
Sensor 11/4”
FC+, FC- Flame Sense
Test Points
2 Pin Header
(TE P/N: 640383-2,
Molex P/N: 26-60-2020)

Effective: November 2015
4 F-35-70
TROUBLESHOOTING
Note: During a fault condition, the LED will flash on for
1/4 second and off for 1/4 second as needed to
indicate the fault code. The code will repeat every
3 seconds. Removing power from the control will
clear the fault code.
Internal Control Failure
If the control detects a software or hardware error, all outputs
are turned off and the LED displays a Steady On condition. If this
condition persists after an attempt to restart, then the control
must be replaced.
Proper Electrode Location
Proper location of electrode assembly is important for optimum
system performance. The electrode assembly should be located
so that the tips are inside the flame envelope and about 1/2-inch
(1.2 cm) above the base of the flame as shown:
Notes:
• Ceramic insulators must not be in or close to the flame.
• Electrode assemblies must not be adjusted or
disassembled. Electrodes are NOT field adjustable.
• Electrodes should have a gap spacing of 0.125± 0.031
in (3.12± 0.81 mm), unless otherwise specified by the
appliance manufacturer. If spacing is not correct, the
assembly must be replaced.
• Exceeding temperature limits can cause nuisance
lockouts and premature electrode failure.
• Electrodes must be located where they are not exposed
during normal operation.
Flame Current Measurement
Flame current is the current that passes through the flame from
sensor to ground. To measure flame current, connect a True
RMS or analog DC micro-ammeter to the FC+ and FC- terminals.
Readings should be 1.0 µA DC or higher. If the meter reads
negative or below "0" on scale, meter leads are reversed. Re-
connect leads with proper polarity.
Alternately, a Digital Voltmeter may be used to measure DC
voltage between FC+ and FC- terminals. Each micro-amp of
flame current produces 1.0 VDC. For example, 2.6 VDC equates
to 2.6 µA.
A good burner ground that matches the control ground is critical
for reliable flame sensing.
Troubleshooting Guide
Symptom Recommended Actions
1. Control does not start A. Miswired
B. No 120VAC at L1
C. Fuse or circuit breaker fault
D. Faulty control, check LED
for fault codes
2. Thermostat on - no spark A. Miswired
B. Faulty thermostat, no
voltage at terminal L1
C. Faulty control, check LED
for fault codes
3. Valve on - no spark during
TFI
A. Shorted electrode -
establish 1/8-inch gap
B. Check high voltage cable
C. Miswired
4. Spark on - valve off A. Valve coil open
B. Valve wire disconnected
C. Faulty control, check
voltage at gas valve
terminal V1
5. Flame okay during TFI - no
flame sense after TFI
A. Check electrode position
B. Check high voltage wire
C. Poor ground at burner
D. Poor flame, check flame
current
Fault Conditions
LED Indication Fault Mode
Steady On Internal Control Failure
2 Flashes Flame without call for heat
3 Flashes Ignition Lockout

Effective: November 2015
F-35-70 5
DIMENSIONS
Figure 4. Enclosure
Figure 6. Integral Standoff
Figure 5. Potted
Note: All dimensions are in inches

This literature is provided for informational purposes only.
KIDDE-FENWAL, INC. assumes no responsibility for the prod-
uct’s suitability for a particular application. The product must be
properly applied to work correctly. If you need more information
on this product, or if you have a particular problem or question,
contact KIDDE-FENWAL, INC., Ashland, MA 01721.
© 2015 Kidde-Fenwal Inc. P/N F-35-70 Rev AA
Fenwal Controls, Kidde-Fenwal Inc.
400 Main Street
Ashland, MA 01721
Tel: 800-FENWAL-1
Fax: [phone]
www.fenwal.com
FENWAL®and DETECT-A-FLAME®are registered trademarks of Kidde-Fenwal Inc.
All other trademarks are the property of their respective owners.
PART NUMBER CONFIGURATION
SERIES 35-705 X 0 X - X X X
Trial for Ignition
1 = 4 Seconds
3 = 7 Seconds
5 = 10 Seconds
7 = 15 Seconds
Inter-Purge
0 = None (Single Try Only)
1 = 15 Seconds
2 = 30 Seconds
Pre-Purge
0 = None
1 = 15 Seconds
2 = 30 Seconds
5 = 5 Seconds
Tries for Ignition, Flame Sense Method and
Reset Method
0 = 1 try, local sense
1 = 1 try, remote sense
2 = 1 try, local sense
3 = 1 try, remote sense
5 = 3 try, local sense
6 = 3 try, remote sense
7 = 3 try, local sense
8 = 3 try, remote sense
Configuration and Wiring options
2 = Potted
3 = Enclosure
4 = Integral Standoffs
5 = Enclosure
6 = Integral Standoffs
7 = Potted
8 = Aftermarket Kit
9 = Special Configuration
An 8 or 9 in this location
(i.e. 35-70 5 901 -113)
indicates a special configuration.
9XX is a sequentially assigned
part number and does not follow
the standard part numbering configuration.
Consult Fenwal for operating characteristics
of this control.
Multi-Pin Connector
Multi-Pin Connector
Multi-Pin Connector
Quick Connect
Quick Connect
Quick Connect
Thermostat / power off reset
Thermostat / power off reset
Automatic reset
Automatic reset
Thermostat / power off reset
Thermostat / power off reset
Automatic reset
Automatic reset