(f)Provide easily accessible, primary voltage terminal block, internal to cabinetry, for single point field connection of electrical supply.
(g)Single point connection for gas inlet must be provided. Internal piping from gas inlet to burners must be factory installed and tested. Field piping from the gas inlet to the burners is not allowed.
(h)Humidifier to prevent
(i)Drain line to include a vacuum breaker to prevent siphon drainage of the tank.
(j)Allowance for combustion air shall be provided in cabinet ventilation design. Option for direct vent of combustion must be available for use with BH exhaust vent.
(4)Gas appliance shall be low emission. Units with Carbon Monoxide (CO) levels higher than 10 ppm and Nitrous Oxide (NOx) levels above 40 ppm are not acceptable.
(a)System shall be rated as a class I appliance certified for use with exhaust vent type B.
XXXXXOR XXXXX
(b)System shall be rated as a class III appliance certified for use with exhaust vent type BH.
XXXXXOR XXXXX
(c)System shall be rated as a class III appliance certified for use with exhaust vent type BH and use with direct vent of combustion air. (Must be specified for factory configuration)
(5)Stainless Steel combustion chamber(s)/heat exchanger(s) shall have flat surfaces to retard scale
(a)Each burner, capable of true modulation will provide steam production of 25 to 105 lbs/hr (11 to 48 kg/hr). Time proportioning modulation is not acceptable.
(b)Units with multiple heat exchangers, models 210 to 630 lbs/hr (95 kg/hr to 286 kg/hr) must be capable of producing a minimum output of 25 lbs/hr (11kg/hr).
(c)Units with multiple heat exchangers, models 210 to 630 lbs/hr (95 kg/hr to 286 kg/hr) must alternate the lead burners (duty cycle) to promote equal usage.
(d)Gas system with gas valve(s), explosion proof, premix combustion air blower(s), microprocessor controlled ignition, flame sensing and fault indicator light(s), 100% premix infrared burner(s), hot surface igniters(s) and heat transfer efficiency maintained over all operating ranges.
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