CSA ANSI Z21.23-2010 pdf free download – American National Standard For Gas Appliance Thermostats.
1.10.2
When means are provided for the user to vary the temperature setting, such means shall clearly indicatethe direction of movement to increase or decrease the temperature and the minimum and maximumoperating positions.One of the dial graduations shall be located at the calibration reference point.1.10.3
Thermostats for use on ovens and broilers shall be provided with dials marked with successively numberedtemperatures not more that 50°F(28″C) apart. Above 200°F (93.5C), graduations shall be provided atleast every 25°F (14C).These thermostats shall be constructed so as to allow the dial to be set at anymarked temperature position.
1.10.4
On adjustable type thermostats, the calibration reference points shall be as shown in Table ll,CalibrationReference Point(s).
For temperature ranges other than those recommended in Table ll, Recommended Dial TemperatureMarkings, the calibration reference point(s) shall be specified by the manufacturer.
1.11 Resistance To Corrosion
The manufacturer shall supply evidence acceptable to the testing agency that all materials have beenevaluated and found to be suitable for their intended usage. Test data based on ASTM or other
appropriate test procedures, certifications or historical data may be submitted for this purpose.Theevidence shall show that the materials have been evaluated, as appropriate for resistance to moisture,corrosion and the effects of fuel gases, including the sulfur compounds therein, and that nonmetallicdiaphragm and seal materials are suitably resistant to the effects of ozone.
1.12 Assembly
1.12.1
The construction of thermostats to be used where certain parts will be immersed in liquids shall be suchthat, in the event of failure of such parts, it will not be possible for liquids to pass into the gas channels.Thermostats constructed so that the only surface exposed to liquids is that of a single piece without jointsor screws, or is constructed with joints or seams which are properly welded, brazed or soldered, shall beconsidered as complying with this provision.
1.12.2
lf an integral gas valve thermostat can be partially or completely disassembled without the use of specialtools, construction shall be such that either:
a. The parts of the thermostat cannot be readily reassembled improperly in a manner which could resultin an unsafe condition; or
b. The standard fasteners are covered with a sealing means to discourage disassembly. The sealing
means shall be suitable for exposure to the minimum and maximum ambient temperatures specifiedfor the control.
This provision does not apply to parts of the thermostat intended for field replacement or servicing (see1.14-f).
1.12.3
When a wire gauze or perforated sheet screen is inserted in the valve body, it shall be fixed so that it maynot be dislodged or deformed so as to interfere with the operation of the valve mechanism in any way.
1.12.4 The construction shall be such that parts which would normally be removed for servicing cannot bereadily misassembled to cause faulty or unsafe operation.
1.13 Electrical Electrical components and wiring supplied as part of the system shall be of approved types or shall beinvestigated as an integral part of the system for construction and performance equivalent to approvedtypes. Electrical components and wiring listed or certified by a nationally recognized testing agency qualified tocertify or list eiectrical equipment or wiring shall be deemed to be an approved type when used within thelimits of its listing or certification. Millivolt circuits need not comply with spacing, insulation, enclosure and grounding provisions whenshorting of such a circuit will not result in unsafe operation of the device.
1.13.1 Insulating Material
a. A joint shall be provided with insulation equivalent to that of the wires involved if permanence of spacing between the joint and uninsulated live metal parts of opposite polarity or grounded deadmetal parts is not assured.
b. Material used shall be judged with respect to its suitability for the particular application. ln determining the suitability of an electrical insulating material, consideration shall be given to itsmechanical strength, dielectric strength, heat and moistureresistant properties, the degree to which itis enclosed or protected, and any other features having a bearing on its application in the device.
1.13.2 Conductors and Connections a. An electrically operated device shall be provided with suitable terminals, connectors or with leadsentering the enclosure through a suitable opening. b. Supply conductors shall have adequate current-carrying capacity. No supply conductor smaller than 18 AWG (0.82 mm2), or its equivalent shall be used, and the insulation shall not be less than ‘/ y in(O.8 mm) in thickness.CSA ANSI Z21.23 pdf download