Lochinvar 90, 500 Heat Exchanger Pressure Drop Chart, Water Connections Heating Boilers Only

Installation & Service Manual

4Hydronic piping (continued)

Hot water piping must be supported by suitable hangers or floor stands, NOT by the boiler. Copper pipe systems will be subject to considerable expansion and contraction. Rigid pipe hangers could allow the pipe to slide in the hanger resulting in noise transmitted into the system. Padding is recommended on rigid hangers installed with a copper system. The boiler pressure relief valve must be piped to a suitable floor drain. See the relief valve section on page 24 of this manual.

￿ CAUTION	A leak in a boiler system will cause the
	system to intake fresh water constantly,
	which will cause the tubes to accumulate
	a lime/scale build up. This will cause a
	NON-WARRANTABLE FAILURE.

Water Connections Heating Boilers Only

All water heaters and heating boilers with inputs of 315,000 - 500,000 Btu/hr have 2" NPT.

￿CAUTION Field installed reducing bushings may decrease flow resulting in boiler noise or

flashing to steam.

Circulator Pump Requirements

This is a low mass, high efficiency hot water boiler which must have adequate flow for quiet, efficient operation. The boiler circulating pump must be purchased locally. The boiler circulator pump must operate continuously while the boiler is firing. Pump selection is critical to achieve proper operation. A pump should be selected to achieve proper system design water temperature rise. A heat exchanger pressure drop chart (Table 4C) is provided to assist in proper pump selection. Also provided is a System Temperature Rise Chart (Table 4B). This table provides GPM and boiler head-loss at various temperature rises for each boiler based on Btu/hr input. Temperature rise is the difference in boiler inlet temperature and boiler outlet temperature while the boiler is firing. Example: The boiler inlet temperature is 160°F and the boiler outlet temperature is 180°F, this means that there is a 20°F temperature rise across the boiler.

TABLE - 4C

HEAT EXCHANGER PRESSURE DROP CHART

	7		CB500
	6
			CB360
	5
FT/HD	4	CB	315
		CB399
	3

2

1

0

0 5 10 15 20 25 30 35

Gallons per Minute

Circulator Pump Operation (Heating Boilers Only)

Boilers are equipped with a relay for controlling the circulation pump for the hot water loop. The relay turns ON and OFF in response to the “W” input from the wall thermostat or zone control.

The field installed boiler pump MUST NOT exceed 1 h.p. For continuous pump operation, wire the system pump to the 120V supply. The pump should be connected at the junction box as shown in FIG. 4-3.

120V

SUPPLY

TO

UNIT

Circulator Pump Specifications

1.Maximum operating pressure for the pump must exceed system operating pressure.

2.Maximum water temperature should not exceed nameplate rating.

3.Cast iron circulators may be used for closed loop systems.

4.A properly sized expansion tank must be installed near the boiler and located on the suction side of the pump.

TO

CIRCULATION

PUMP

Figure 4-3_Boiler Wiring - Circulation Pump to Junction Box

27