Burnham MST288, MST396 manual P. Aquastat Controller Installation Boilers with Tankless Heater only

7.Screw LWCO to External Wiring Enclosure wiring harness (end with fork and female disconnect terminals) connector into low water cut-off J-box top fitting, and attach wires to the terminals per

LWCO wiring detail shown in Figure 9 "Float-Type LWCO and Gauge Glass Installation".

8.Re-install #67 LWCO J-box cover.

9.Pick-up the LWCO harness Molex end and feed it into the enclosure, thru external electrical enclosure top flange front left 7/8” hole; then, snap-in harness

BX connector into the hole, and, plug-in Molex connector into dedicated LWCO receptacle inside the enclosure (middle left off transformer/relay). See

“ Control Plug-In Diagram” label attached to inside of the enclosure cover for details.

10.Pick-up the pressure limit harness Molex end and feed it into the enclosure, thru External

Electrical Enclosure top flange rear left 7/8” hole; then, snap-in harness BX connector into the hole, and, plug-in Molex connector into dedicated pressure limit receptacle inside the enclosure (upper left off transformer/relay). See “ Control Plug-In Diagram” label attached to inside of the enclosure cover for details.

P.Aquastat Controller Installation (Boilers with Tankless Heater only).

1. On boilers with tankless heater, install the L4006A aquastat controller well (found in Part Carton) into ½” NPT tapping in tankless heater plate.

2. Remove the L4006A aquastat controller with factory attached harness from Control Carton.

3. Slip the bulb of the aquastat controller into the well and secure the controller in place with the set screw.

WARNING

Aquastat bulb must be fully inserted into the well.

4.Feed the L4006A aquastat controller harness end thru external electrical enclosure top flange middle right bushed hole. See “ Control Plug-In Diagram” label attached to inside of the enclosure cover for details.

5.See Figures 18, 19 and 20 (whichever applicable) for tankless heater aquastat connection details.

6.Using needle nose pliers form hook on harness each stripped end and wrap hooks around screws under terminals "R" and "G" of the R8285C Transformer- Relay; then, tighten screws securely.

Q.Safety Valve and Drain Valve Installation.

1.Remove safety valve and related piping (3/4”

NPT x 3” lg. black nipple, 3/4” NPT x 8” lg. black

nipple, ¾” NPT 90° black elbow and ¾” NPT black coupling) from Part Carton.

2.Thread 3/4" NPT x 3” lg. black nipple into rear section safety valve tapping, install ¾” NPT 90° black elbow facing upward, then, thread 3/4" NPT x 8” lg. black nipple into the elbow, and, install ¾” NPT black coupling onto nipple end.

3.Thread safety valve into the ¾” NPT black coupling.

Pipe the safety valve discharge as shown in Figure 11 “ Recommended Boiler Piping For Gravity Return Steam Boiler” shown in Section III of this manual. Installation of the safety valve must be consistent with ANSI/ASME Boiler and Pressure Vessel Code, Section IV.

WARNING

Safety valve discharge piping must be piped near floor to eliminate potential of severe burns. Do not pipe in any area where freezing could occur. Do not install any shut-off valves, plugs or caps.

4.Remove 1-1/2" NPT x 5” lg. black nipple, 1-1/2” x 1-1/2” x ¾” NPT black tee and drain valve from

Part Carton.

NOTICE

Lower rear section Tapping "H" is used for standard condensate return on steam boilers.

5.Thread 1-1/2" NPT x 5” lg. black nipple into lower rear section tapping, then, install 1-1/2” x 1-1/2” x

¾” NPT black tee onto nipple end. Black tee side outlet may be oriented to either left, or, right side.

6.Install the drain valve into black tee ¾” NPT side outlet.

R. Oil Burner Installation.

1.Install oil burner, refer to Figure 10.

a.Open burner carton and remove contents.

b.Check oil nozzle in burner for size, angle and type, inspect electrode settings, check head setting, check air band and air shutter settings, refer to Table 8 at rear of this manual.

c.Place oil burner gasket on burner and align holes.

CAUTION

Do not install burner without gasket.

d.Remove three (3) 5/16-18 x 3/4 lg. cap screw from burner swing door used for mounting burner.

e.Thread (1) 5/16-18 x 3/4 lg. cap screw, approximately three (3) full turns, into tapping located at 12:00 o'clock on burner swing door.

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